diff --git a/go.mod b/go.mod
index 81f8cb7a5aa..02ceb4b863c 100644
--- a/go.mod
+++ b/go.mod
@@ -22,7 +22,6 @@ require (
 	github.com/julienschmidt/httprouter v1.3.0
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/kevinburke/ssh_config v1.1.0 // indirect
-	github.com/mattn/go-colorable v0.1.9 // indirect
 	github.com/mattn/go-isatty v0.0.14
 	github.com/mgutz/ansi v0.0.0-20200706080929-d51e80ef957d // indirect
 	github.com/mitchellh/go-homedir v1.1.0
@@ -31,6 +30,7 @@ require (
 	github.com/opencontainers/runc v1.0.2 // indirect
 	github.com/opencontainers/selinux v1.10.0
 	github.com/pkg/errors v0.9.1
+	github.com/rhysd/actionlint v1.6.8
 	github.com/robertkrimen/otto v0.0.0-20210614181706-373ff5438452
 	github.com/sabhiram/go-gitignore v0.0.0-20201211210132-54b8a0bf510f
 	github.com/sergi/go-diff v1.2.0 // indirect
@@ -41,7 +41,6 @@ require (
 	github.com/xanzy/ssh-agent v0.3.1 // indirect
 	golang.org/x/crypto v0.0.0-20210921155107-089bfa567519 // indirect
 	golang.org/x/net v0.0.0-20210917221730-978cfadd31cf // indirect
-	golang.org/x/sys v0.0.0-20210923061019-b8560ed6a9b7 // indirect
 	golang.org/x/term v0.0.0-20210916214954-140adaaadfaf
 	golang.org/x/text v0.3.7 // indirect
 	google.golang.org/genproto v0.0.0-20210921142501-181ce0d877f6 // indirect
diff --git a/go.sum b/go.sum
index 4615e8aa237..f791e1eacc7 100644
--- a/go.sum
+++ b/go.sum
@@ -425,6 +425,7 @@ github.com/docker/spdystream v0.0.0-20160310174837-449fdfce4d96/go.mod h1:Qh8CwZ
 github.com/docopt/docopt-go v0.0.0-20180111231733-ee0de3bc6815/go.mod h1:WwZ+bS3ebgob9U8Nd0kOddGdZWjyMGR8Wziv+TBNwSE=
 github.com/dustin/go-humanize v0.0.0-20171111073723-bb3d318650d4/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
 github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
+github.com/dvyukov/go-fuzz v0.0.0-20210914135545-4980593459a1/go.mod h1:11Gm+ccJnvAhCNLlf5+cS9KjtbaD5I5zaZpFMsTHWTw=
 github.com/eapache/go-resiliency v1.1.0/go.mod h1:kFI+JgMyC7bLPUVY133qvEBtVayf5mFgVsvEsIPBvNs=
 github.com/eapache/go-xerial-snappy v0.0.0-20180814174437-776d5712da21/go.mod h1:+020luEh2TKB4/GOp8oxxtq0Daoen/Cii55CzbTV6DU=
 github.com/eapache/queue v1.1.0/go.mod h1:6eCeP0CKFpHLu8blIFXhExK/dRa7WDZfr6jVFPTqq+I=
@@ -446,6 +447,8 @@ github.com/evanphx/json-patch v4.2.0+incompatible/go.mod h1:50XU6AFN0ol/bzJsmQLi
 github.com/evanphx/json-patch v4.9.0+incompatible/go.mod h1:50XU6AFN0ol/bzJsmQLiYLvXMP4fmwYFNcr97nuDLSk=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
 github.com/fatih/color v1.9.0/go.mod h1:eQcE1qtQxscV5RaZvpXrrb8Drkc3/DdQ+uUYCNjL+zU=
+github.com/fatih/color v1.13.0 h1:8LOYc1KYPPmyKMuN8QV2DNRWNbLo6LZ0iLs8+mlH53w=
+github.com/fatih/color v1.13.0/go.mod h1:kLAiJbzzSOZDVNGyDpeOxJ47H46qBXwg5ILebYFFOfk=
 github.com/felixge/httpsnoop v1.0.2/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI435gkrCt3MPfRiAkVrwSbHsst4LCFVfpJc=
 github.com/form3tech-oss/jwt-go v3.2.2+incompatible/go.mod h1:pbq4aXjuKjdthFRnoDwaVPLA+WlJuPGy+QneDUgJi2k=
@@ -825,8 +828,9 @@ github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcncea
 github.com/mattn/go-colorable v0.1.2/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
 github.com/mattn/go-colorable v0.1.4/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
 github.com/mattn/go-colorable v0.1.6/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
-github.com/mattn/go-colorable v0.1.9 h1:sqDoxXbdeALODt0DAeJCVp38ps9ZogZEAXjus69YV3U=
 github.com/mattn/go-colorable v0.1.9/go.mod h1:u6P/XSegPjTcexA+o6vUJrdnUu04hMope9wVRipJSqc=
+github.com/mattn/go-colorable v0.1.11 h1:nQ+aFkoE2TMGc0b68U2OKSexC+eq46+XwZzWXHRmPYs=
+github.com/mattn/go-colorable v0.1.11/go.mod h1:u5H1YNBxpqRaxsYJYSkiCWKzEfiAb1Gb520KVy5xxl4=
 github.com/mattn/go-ieproxy v0.0.0-20190610004146-91bb50d98149/go.mod h1:31jz6HNzdxOmlERGGEc4v/dMssOfmp2p5bT/okiKFFc=
 github.com/mattn/go-ieproxy v0.0.0-20190702010315-6dee0af9227d/go.mod h1:31jz6HNzdxOmlERGGEc4v/dMssOfmp2p5bT/okiKFFc=
 github.com/mattn/go-ieproxy v0.0.1/go.mod h1:pYabZ6IHcRpFh7vIaLfK7rdcWgFEb3SFJ6/gNWuh88E=
@@ -839,6 +843,8 @@ github.com/mattn/go-isatty v0.0.12/go.mod h1:cbi8OIDigv2wuxKPP5vlRcQ1OAZbq2CE4Ky
 github.com/mattn/go-isatty v0.0.14 h1:yVuAays6BHfxijgZPzw+3Zlu5yQgKGP2/hcQbHb7S9Y=
 github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94=
 github.com/mattn/go-runewidth v0.0.2/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
+github.com/mattn/go-runewidth v0.0.13 h1:lTGmDsbAYt5DmK6OnoV7EuIF1wEIFAcxld6ypU4OSgU=
+github.com/mattn/go-runewidth v0.0.13/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/mattn/go-shellwords v1.0.3/go.mod h1:3xCvwCdWdlDJUrvuMn7Wuy9eWs4pE8vqg+NOMyg4B2o=
 github.com/mattn/go-shellwords v1.0.10/go.mod h1:EZzvwXDESEeg03EKmM+RmDnNOPKG4lLtQsUlTZDWQ8Y=
 github.com/mattn/go-sqlite3 v1.9.0/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
@@ -1027,8 +1033,14 @@ github.com/quasilyte/go-consistent v0.0.0-20190521200055-c6f3937de18c/go.mod h1:
 github.com/quasilyte/go-ruleguard v0.1.2-0.20200318202121-b00d7a75d3d8/go.mod h1:CGFX09Ci3pq9QZdj86B+VGIdNj4VyCo2iPOGS9esB/k=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
 github.com/remyoudompheng/bigfft v0.0.0-20170806203942-52369c62f446/go.mod h1:uYEyJGbgTkfkS4+E/PavXkNJcbFIpEtjt2B0KDQ5+9M=
+github.com/rhysd/actionlint v1.6.8 h1:li0691FNuuS3da2igfjMb9M58AgMXX7j9U5EgbCZFuc=
+github.com/rhysd/actionlint v1.6.8/go.mod h1:0AA4pvZ2nrZHT6D86eUhieH2NFmLqhxrNex0NEa2A2g=
+github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
+github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/robertkrimen/otto v0.0.0-20210614181706-373ff5438452 h1:ewTtJ72GFy2e0e8uyiDwMG3pKCS5mBh+hdSTYsPKEP8=
 github.com/robertkrimen/otto v0.0.0-20210614181706-373ff5438452/go.mod h1:xvqspoSXJTIpemEonrMDFq6XzwHYYgToXWj5eRX1OtY=
+github.com/robfig/cron v1.2.0 h1:ZjScXvvxeQ63Dbyxy76Fj3AT3Ut0aKsyd2/tl3DTMuQ=
+github.com/robfig/cron v1.2.0/go.mod h1:JGuDeoQd7Z6yL4zQhZ3OPEVHB7fL6Ka6skscFHfmt2k=
 github.com/rogpeppe/fastuuid v0.0.0-20150106093220-6724a57986af/go.mod h1:XWv6SoW27p1b0cqNHllgS5HIMJraePCO15w5zCzIWYg=
 github.com/rogpeppe/fastuuid v1.1.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
@@ -1189,6 +1201,7 @@ github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9de
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.3.5/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
+github.com/yuin/goldmark v1.4.0/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 github.com/yvasiyarov/go-metrics v0.0.0-20140926110328-57bccd1ccd43/go.mod h1:aX5oPXxHm3bOH+xeAttToC8pqch2ScQN/JoXYupl6xs=
 github.com/yvasiyarov/gorelic v0.0.0-20141212073537-a9bba5b9ab50/go.mod h1:NUSPSUX/bi6SeDMUh6brw0nXpxHnc96TguQh0+r/ssA=
 github.com/yvasiyarov/newrelic_platform_go v0.0.0-20140908184405-b21fdbd4370f/go.mod h1:GlGEuHIJweS1mbCqG+7vt2nvWLzLLnRHbXz5JKd/Qbg=
@@ -1395,6 +1408,7 @@ golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c h1:5KslGYwFpkhGh+Q16bwMP3cOontH8FOep7tGV86Y7SQ=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20170830134202-bb24a47a89ea/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180823144017-11551d06cbcc/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -1494,8 +1508,9 @@ golang.org/x/sys v0.0.0-20210502180810-71e4cd670f79/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.0.0-20210923061019-b8560ed6a9b7 h1:c20P3CcPbopVp2f7099WLOqSNKURf30Z0uq66HpijZY=
-golang.org/x/sys v0.0.0-20210923061019-b8560ed6a9b7/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20211113001501-0c823b97ae02 h1:7NCfEGl0sfUojmX78nK9pBJuUlSZWEJA/TwASvfiPLo=
+golang.org/x/sys v0.0.0-20211113001501-0c823b97ae02/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210503060354-a79de5458b56/go.mod h1:tfny5GFUkzUvx4ps4ajbZsCe5lw1metzhBm9T3x7oIY=
diff --git a/pkg/exprparser/functions.go b/pkg/exprparser/functions.go
new file mode 100644
index 00000000000..58c08903357
--- /dev/null
+++ b/pkg/exprparser/functions.go
@@ -0,0 +1,282 @@
+package exprparser
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strconv"
+	"strings"
+
+	"github.com/nektos/act/pkg/model"
+)
+
+func (impl *interperterImpl) contains(search, item reflect.Value) (bool, error) {
+	switch search.Kind() {
+	case reflect.String, reflect.Int, reflect.Float64, reflect.Bool, reflect.Invalid:
+		return strings.Contains(
+			strings.ToLower(impl.coerceToString(search).String()),
+			strings.ToLower(impl.coerceToString(item).String()),
+		), nil
+
+	case reflect.Slice:
+		switch item.Kind() {
+		case reflect.String, reflect.Int, reflect.Float64, reflect.Bool, reflect.Invalid:
+			itemStr := strings.ToLower(impl.coerceToString(item).String())
+
+			for i := 0; i < search.Len(); i++ {
+				if strings.ToLower(impl.coerceToString(search.Index(i).Elem()).String()) == itemStr {
+					return true, nil
+				}
+			}
+
+		case reflect.Slice, reflect.Struct:
+			for i := 0; i < search.Len(); i++ {
+				if search.Index(i).Elem() == item {
+					return true, nil
+				}
+			}
+		}
+	}
+
+	return false, nil
+}
+
+func (impl *interperterImpl) startsWith(searchString, searchValue reflect.Value) (bool, error) {
+	return strings.HasPrefix(
+		strings.ToLower(impl.coerceToString(searchString).String()),
+		strings.ToLower(impl.coerceToString(searchValue).String()),
+	), nil
+}
+
+func (impl *interperterImpl) endsWith(searchString, searchValue reflect.Value) (bool, error) {
+	return strings.HasSuffix(
+		strings.ToLower(impl.coerceToString(searchString).String()),
+		strings.ToLower(impl.coerceToString(searchValue).String()),
+	), nil
+}
+
+const (
+	passThrough = iota
+	bracketOpen
+	bracketClose
+)
+
+func (impl *interperterImpl) format(str reflect.Value, replaceValue ...reflect.Value) (string, error) {
+	input := impl.coerceToString(str).String()
+	output := ""
+	replacementIndex := ""
+
+	state := passThrough
+	for _, character := range input {
+		switch state {
+		case passThrough: // normal buffer output
+			switch character {
+			case '{':
+				state = bracketOpen
+
+			case '}':
+				state = bracketClose
+
+			default:
+				output += string(character)
+			}
+
+		case bracketOpen: // found {
+			switch character {
+			case '{':
+				output += "{"
+				replacementIndex = ""
+				state = passThrough
+
+			case '}':
+				index, err := strconv.ParseInt(replacementIndex, 10, 32)
+				if err != nil {
+					return "", fmt.Errorf("The following format string is invalid: '%s'", input)
+				}
+
+				replacementIndex = ""
+
+				if len(replaceValue) <= int(index) {
+					return "", fmt.Errorf("The following format string references more arguments than were supplied: '%s'", input)
+				}
+
+				output += impl.coerceToString(replaceValue[index]).String()
+
+				state = passThrough
+
+			default:
+				replacementIndex += string(character)
+			}
+
+		case bracketClose: // found }
+			switch character {
+			case '}':
+				output += "}"
+				replacementIndex = ""
+				state = passThrough
+
+			default:
+				panic("Invalid format parser state")
+			}
+		}
+	}
+
+	if state != passThrough {
+		switch state {
+		case bracketOpen:
+			return "", fmt.Errorf("Unclosed brackets. The following format string is invalid: '%s'", input)
+
+		case bracketClose:
+			return "", fmt.Errorf("Closing bracket without opening one. The following format string is invalid: '%s'", input)
+		}
+	}
+
+	return output, nil
+}
+
+func (impl *interperterImpl) join(array reflect.Value, sep reflect.Value) (string, error) {
+	separator := impl.coerceToString(sep).String()
+	switch array.Kind() {
+	case reflect.Slice:
+		var items []string
+		for i := 0; i < array.Len(); i++ {
+			items = append(items, impl.coerceToString(array.Index(i).Elem()).String())
+		}
+
+		return strings.Join(items, separator), nil
+	default:
+		return strings.Join([]string{impl.coerceToString(array).String()}, separator), nil
+	}
+}
+
+func (impl *interperterImpl) toJSON(value reflect.Value) (string, error) {
+	if value.Kind() == reflect.Invalid {
+		return "", nil
+	}
+
+	json, err := json.MarshalIndent(value.Interface(), "", "  ")
+	if err != nil {
+		return "", fmt.Errorf("Cannot convert value to JSON. Cause: %v", err)
+	}
+
+	return string(json), nil
+}
+
+func (impl *interperterImpl) fromJSON(value reflect.Value) (interface{}, error) {
+	if value.Kind() != reflect.String {
+		return nil, fmt.Errorf("Cannot parse non-string type %v as JSON", value.Kind())
+	}
+
+	var data interface{}
+
+	err := json.Unmarshal([]byte(value.String()), &data)
+	if err != nil {
+		return nil, fmt.Errorf("Invalid JSON: %v", err)
+	}
+
+	return data, nil
+}
+
+func (impl *interperterImpl) hashFiles(paths ...reflect.Value) (string, error) {
+	var filepaths []string
+
+	for _, path := range paths {
+		if path.Kind() == reflect.String {
+			filepaths = append(filepaths, path.String())
+		} else {
+			return "", fmt.Errorf("Non-string path passed to hashFiles")
+		}
+	}
+
+	var files []string
+
+	for i := range filepaths {
+		newFiles, err := filepath.Glob(filepath.Join(impl.config.WorkingDir, filepaths[i]))
+		if err != nil {
+			return "", fmt.Errorf("Unable to glob.Glob: %v", err)
+		}
+
+		files = append(files, newFiles...)
+	}
+
+	if len(files) == 0 {
+		return "", nil
+	}
+
+	hasher := sha256.New()
+
+	for _, file := range files {
+		f, err := os.Open(file)
+		if err != nil {
+			return "", fmt.Errorf("Unable to os.Open: %v", err)
+		}
+
+		if _, err := io.Copy(hasher, f); err != nil {
+			return "", fmt.Errorf("Unable to io.Copy: %v", err)
+		}
+
+		if err := f.Close(); err != nil {
+			return "", fmt.Errorf("Unable to Close file: %v", err)
+		}
+	}
+
+	return hex.EncodeToString(hasher.Sum(nil)), nil
+}
+
+func (impl *interperterImpl) getNeedsTransitive(job *model.Job) []string {
+	needs := job.Needs()
+
+	for _, need := range needs {
+		parentNeeds := impl.getNeedsTransitive(impl.config.Run.Workflow.GetJob(need))
+		needs = append(needs, parentNeeds...)
+	}
+
+	return needs
+}
+
+func (impl *interperterImpl) always() (bool, error) {
+	return true, nil
+}
+
+func (impl *interperterImpl) jobSuccess() (bool, error) {
+	jobs := impl.config.Run.Workflow.Jobs
+	jobNeeds := impl.getNeedsTransitive(impl.config.Run.Job())
+
+	for _, needs := range jobNeeds {
+		if jobs[needs].Result != "success" {
+			return false, nil
+		}
+	}
+
+	return true, nil
+}
+
+func (impl *interperterImpl) stepSuccess() (bool, error) {
+	return impl.env.Job.Status == "success", nil
+}
+
+func (impl *interperterImpl) jobFailure() (bool, error) {
+	jobs := impl.config.Run.Workflow.Jobs
+	jobNeeds := impl.getNeedsTransitive(impl.config.Run.Job())
+
+	for _, needs := range jobNeeds {
+		if jobs[needs].Result == "failure" {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func (impl *interperterImpl) stepFailure() (bool, error) {
+	return impl.env.Job.Status == "failure", nil
+}
+
+func (impl *interperterImpl) cancelled() (bool, error) {
+	return impl.env.Job.Status == "cancelled", nil
+}
diff --git a/pkg/exprparser/functions_test.go b/pkg/exprparser/functions_test.go
new file mode 100644
index 00000000000..253d1807e3b
--- /dev/null
+++ b/pkg/exprparser/functions_test.go
@@ -0,0 +1,247 @@
+package exprparser
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/nektos/act/pkg/model"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFunctionContains(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"contains('search', 'item') }}", false, "contains-str-str"},
+		{`cOnTaInS('Hello', 'll') }}`, true, "contains-str-casing"},
+		{`contains('HELLO', 'll') }}`, true, "contains-str-casing"},
+		{`contains('3.141592', 3.14) }}`, true, "contains-str-number"},
+		{`contains(3.141592, '3.14') }}`, true, "contains-number-str"},
+		{`contains(3.141592, 3.14) }}`, true, "contains-number-number"},
+		{`contains(true, 'u') }}`, true, "contains-bool-str"},
+		{`contains(null, '') }}`, true, "contains-null-str"},
+		{`contains(fromJSON('["first","second"]'), 'first') }}`, true, "contains-item"},
+		{`contains(fromJSON('[null,"second"]'), '') }}`, true, "contains-item-null-empty-str"},
+		{`contains(fromJSON('["","second"]'), null) }}`, true, "contains-item-empty-str-null"},
+		// TODO: investigate why this evaluates to false
+		// {`contains(fromJSON('[true,"second"]'), 'true') }}`, true, "contains-item-bool-arr"},
+		// TODO: investigate why this evaluates to false
+		// {`contains(fromJSON('["true","second"]'), true) }}`, true, "contains-item-str-bool"},
+		{`contains(fromJSON('[3.14,"second"]'), '3.14') }}`, true, "contains-item-number-str"},
+		{`contains(fromJSON('[3.14,"second"]'), 3.14) }}`, true, "contains-item-number-number"},
+		{`contains(fromJSON('["","second"]'), fromJSON('[]')) }}`, false, "contains-item-str-arr"},
+		{`contains(fromJSON('["","second"]'), fromJSON('{}')) }}`, false, "contains-item-str-obj"},
+	}
+
+	env := &EvaluationEnvironment{}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestFunctionStartsWith(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"startsWith('search', 'se') }}", true, "startswith-string"},
+		{"startsWith('search', 'sa') }}", false, "startswith-string"},
+		{"startsWith('123search', '123s') }}", true, "startswith-string"},
+		{"startsWith(123, 's') }}", false, "startswith-string"},
+		{"startsWith(123, '12') }}", true, "startswith-string"},
+		{"startsWith('123', 12) }}", true, "startswith-string"},
+		{"startsWith(null, '42') }}", false, "startswith-string"},
+		{"startsWith('null', null) }}", true, "startswith-string"},
+		{"startsWith('null', '') }}", true, "startswith-string"},
+	}
+
+	env := &EvaluationEnvironment{}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestFunctionEndsWith(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"endsWith('search', 'ch') }}", true, "endsWith-string"},
+		{"endsWith('search', 'sa') }}", false, "endsWith-string"},
+		{"endsWith('search123s', '123s') }}", true, "endsWith-string"},
+		{"endsWith(123, 's') }}", false, "endsWith-string"},
+		{"endsWith(123, '23') }}", true, "endsWith-string"},
+		{"endsWith('123', 23) }}", true, "endsWith-string"},
+		{"endsWith(null, '42') }}", false, "endsWith-string"},
+		{"endsWith('null', null) }}", true, "endsWith-string"},
+		{"endsWith('null', '') }}", true, "endsWith-string"},
+	}
+
+	env := &EvaluationEnvironment{}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestFunctionJoin(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"join(fromJSON('[\"a\", \"b\"]'), ',')", "a,b", "join-arr"},
+		{"join('string', ',')", "string", "join-str"},
+		{"join(1, ',')", "1", "join-number"},
+		{"join(null, ',')", "", "join-number"},
+		{"join(fromJSON('[\"a\", \"b\", null]'), null)", "ab", "join-number"},
+		{"join(fromJSON('[\"a\", \"b\"]'))", "a,b", "join-number"},
+		{"join(fromJSON('[\"a\", \"b\", null]'), 1)", "a1b1", "join-number"},
+	}
+
+	env := &EvaluationEnvironment{}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestFunctionToJSON(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"toJSON(env) }}", "{\n  \"key\": \"value\"\n}", "toJSON"},
+	}
+
+	env := &EvaluationEnvironment{
+		Env: map[string]string{
+			"key": "value",
+		},
+	}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestFunctionFromJSON(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"fromJSON('{\"foo\":\"bar\"}') }}", map[string]interface{}{
+			"foo": "bar",
+		}, "fromJSON"},
+	}
+
+	env := &EvaluationEnvironment{}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestFunctionHashFiles(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"hashFiles('**/non-extant-files') }}", "", "hash-non-existing-file"},
+		{"hashFiles('**/non-extant-files', '**/more-non-extant-files') }}", "", "hash-multiple-non-existing-files"},
+		{"hashFiles('./for-hashing-1.txt') }}", "66a045b452102c59d840ec097d59d9467e13a3f34f6494e539ffd32c1bb35f18", "hash-single-file"},
+		{"hashFiles('./for-hashing-*') }}", "8e5935e7e13368cd9688fe8f48a0955293676a021562582c7e848dafe13fb046", "hash-multiple-files"},
+	}
+
+	env := &EvaluationEnvironment{}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			workdir, err := filepath.Abs("testdata")
+			assert.Nil(t, err)
+			output, err := NewInterpeter(env, Config{WorkingDir: workdir}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestFunctionFormat(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		error    interface{}
+		name     string
+	}{
+		{"format('text')", "text", nil, "format-plain-string"},
+		{"format('Hello {0} {1} {2}!', 'Mona', 'the', 'Octocat')", "Hello Mona the Octocat!", nil, "format-with-placeholders"},
+		{"format('{{Hello {0} {1} {2}!}}', 'Mona', 'the', 'Octocat')", "{Hello Mona the Octocat!}", nil, "format-with-escaped-braces"},
+		{"format('{{0}}', 'test')", "{0}", nil, "format-with-escaped-braces"},
+		{"format('{{{0}}}', 'test')", "{test}", nil, "format-with-escaped-braces-and-value"},
+		{"format('}}')", "}", nil, "format-output-closing-brace"},
+		{`format('Hello "{0}" {1} {2} {3} {4}', null, true, -3.14, NaN, Infinity)`, `Hello "" true -3.14 NaN Infinity`, nil, "format-with-primitives"},
+		{`format('Hello "{0}" {1} {2}', fromJSON('[0, true, "abc"]'), fromJSON('[{"a":1}]'), fromJSON('{"a":{"b":1}}'))`, `Hello "Array" Array Object`, nil, "format-with-complex-types"},
+		{"format(true)", "true", nil, "format-with-primitive-args"},
+		{"format('echo Hello {0} ${{Test}}', github.undefined_property)", "echo Hello  ${Test}", nil, "format-with-undefined-value"},
+		{"format('{0}}', '{1}', 'World')", nil, "Closing bracket without opening one. The following format string is invalid: '{0}}'", "format-invalid-format-string"},
+		{"format('{0', '{1}', 'World')", nil, "Unclosed brackets. The following format string is invalid: '{0'", "format-invalid-format-string"},
+		{"format('{2}', '{1}', 'World')", "", "The following format string references more arguments than were supplied: '{2}'", "format-invalid-replacement-reference"},
+		{"format('{2147483648}')", "", "The following format string is invalid: '{2147483648}'", "format-invalid-replacement-reference"},
+	}
+
+	env := &EvaluationEnvironment{
+		Github: &model.GithubContext{},
+	}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			if tt.error != nil {
+				assert.Equal(t, tt.error, err.Error())
+			} else {
+				assert.Nil(t, err)
+				assert.Equal(t, tt.expected, output)
+			}
+		})
+	}
+}
diff --git a/pkg/exprparser/interpreter.go b/pkg/exprparser/interpreter.go
new file mode 100644
index 00000000000..f3d610dfd70
--- /dev/null
+++ b/pkg/exprparser/interpreter.go
@@ -0,0 +1,572 @@
+package exprparser
+
+import (
+	"fmt"
+	"math"
+	"reflect"
+	"strings"
+
+	"github.com/nektos/act/pkg/model"
+	"github.com/rhysd/actionlint"
+)
+
+type EvaluationEnvironment struct {
+	Github   *model.GithubContext
+	Env      map[string]string
+	Job      *model.JobContext
+	Steps    map[string]*model.StepResult
+	Runner   map[string]interface{}
+	Secrets  map[string]string
+	Strategy map[string]interface{}
+	Matrix   map[string]interface{}
+	Needs    map[string]map[string]map[string]string
+	Inputs   map[string]string
+}
+
+type Config struct {
+	Run        *model.Run
+	WorkingDir string
+	Context    string
+}
+
+type Interpreter interface {
+	Evaluate(input string, isIfExpression bool) (interface{}, error)
+}
+
+type interperterImpl struct {
+	env    *EvaluationEnvironment
+	config Config
+}
+
+func NewInterpeter(env *EvaluationEnvironment, config Config) Interpreter {
+	return &interperterImpl{
+		env:    env,
+		config: config,
+	}
+}
+
+func (impl *interperterImpl) Evaluate(input string, isIfExpression bool) (interface{}, error) {
+	input = strings.TrimPrefix(input, "${{")
+	parser := actionlint.NewExprParser()
+	exprNode, err := parser.Parse(actionlint.NewExprLexer(input + "}}"))
+	if err != nil {
+		return nil, fmt.Errorf("Failed to parse: %s", err.Message)
+	}
+
+	if isIfExpression {
+		hasStatusCheckFunction := false
+		actionlint.VisitExprNode(exprNode, func(node, _ actionlint.ExprNode, entering bool) {
+			if funcCallNode, ok := node.(*actionlint.FuncCallNode); entering && ok {
+				switch strings.ToLower(funcCallNode.Callee) {
+				case "success", "always", "cancelled", "failure":
+					hasStatusCheckFunction = true
+				}
+			}
+		})
+
+		if !hasStatusCheckFunction {
+			exprNode = &actionlint.LogicalOpNode{
+				Kind: actionlint.LogicalOpNodeKindAnd,
+				Left: &actionlint.FuncCallNode{
+					Callee: "success",
+					Args:   []actionlint.ExprNode{},
+				},
+				Right: exprNode,
+			}
+		}
+	}
+
+	result, err2 := impl.evaluateNode(exprNode)
+
+	return result, err2
+}
+
+func (impl *interperterImpl) evaluateNode(exprNode actionlint.ExprNode) (interface{}, error) {
+	switch node := exprNode.(type) {
+	case *actionlint.VariableNode:
+		return impl.evaluateVariable(node)
+	case *actionlint.BoolNode:
+		return node.Value, nil
+	case *actionlint.NullNode:
+		return nil, nil
+	case *actionlint.IntNode:
+		return node.Value, nil
+	case *actionlint.FloatNode:
+		return node.Value, nil
+	case *actionlint.StringNode:
+		return node.Value, nil
+	case *actionlint.IndexAccessNode:
+		return impl.evaluateIndexAccess(node)
+	case *actionlint.ObjectDerefNode:
+		return impl.evaluateObjectDeref(node)
+	case *actionlint.ArrayDerefNode:
+		return impl.evaluateArrayDeref(node)
+	case *actionlint.NotOpNode:
+		return impl.evaluateNot(node)
+	case *actionlint.CompareOpNode:
+		return impl.evaluateCompare(node)
+	case *actionlint.LogicalOpNode:
+		return impl.evaluateLogicalCompare(node)
+	case *actionlint.FuncCallNode:
+		return impl.evaluateFuncCall(node)
+	default:
+		return nil, fmt.Errorf("Fatal error! Unknown node type: %s node: %+v", reflect.TypeOf(exprNode), exprNode)
+	}
+}
+
+func (impl *interperterImpl) evaluateVariable(variableNode *actionlint.VariableNode) (interface{}, error) {
+	switch strings.ToLower(variableNode.Name) {
+	case "github":
+		return impl.env.Github, nil
+	case "env":
+		return impl.env.Env, nil
+	case "job":
+		return impl.env.Job, nil
+	case "steps":
+		return impl.env.Steps, nil
+	case "runner":
+		return impl.env.Runner, nil
+	case "secrets":
+		return impl.env.Secrets, nil
+	case "strategy":
+		return impl.env.Strategy, nil
+	case "matrix":
+		return impl.env.Matrix, nil
+	case "needs":
+		return impl.env.Needs, nil
+	case "inputs":
+		return impl.env.Inputs, nil
+	case "infinity":
+		return math.Inf(1), nil
+	case "nan":
+		return math.NaN(), nil
+	default:
+		return nil, fmt.Errorf("Unavailable context: %s", variableNode.Name)
+	}
+}
+
+func (impl *interperterImpl) evaluateIndexAccess(indexAccessNode *actionlint.IndexAccessNode) (interface{}, error) {
+	left, err := impl.evaluateNode(indexAccessNode.Operand)
+	if err != nil {
+		return nil, err
+	}
+
+	leftValue := reflect.ValueOf(left)
+
+	right, err := impl.evaluateNode(indexAccessNode.Index)
+	if err != nil {
+		return nil, err
+	}
+
+	rightValue := reflect.ValueOf(right)
+
+	switch rightValue.Kind() {
+	case reflect.String:
+		return impl.getPropertyValue(leftValue, rightValue.String())
+
+	case reflect.Int:
+		switch leftValue.Kind() {
+		case reflect.Slice:
+			return leftValue.Index(int(rightValue.Int())).Interface(), nil
+		default:
+			return nil, fmt.Errorf("Unable to index on non-slice value: %s", leftValue.Kind())
+		}
+
+	default:
+		return nil, fmt.Errorf("Unknown index type: %s", rightValue.Kind())
+	}
+}
+
+func (impl *interperterImpl) evaluateObjectDeref(objectDerefNode *actionlint.ObjectDerefNode) (interface{}, error) {
+	left, err := impl.evaluateNode(objectDerefNode.Receiver)
+	if err != nil {
+		return nil, err
+	}
+
+	return impl.getPropertyValue(reflect.ValueOf(left), objectDerefNode.Property)
+}
+
+func (impl *interperterImpl) evaluateArrayDeref(arrayDerefNode *actionlint.ArrayDerefNode) (interface{}, error) {
+	left, err := impl.evaluateNode(arrayDerefNode.Receiver)
+	if err != nil {
+		return nil, err
+	}
+
+	return reflect.ValueOf(left).Interface(), nil
+}
+
+func (impl *interperterImpl) getPropertyValue(left reflect.Value, property string) (value interface{}, err error) {
+	switch left.Kind() {
+	case reflect.Ptr:
+		return impl.getPropertyValue(left.Elem(), property)
+
+	case reflect.Struct:
+		leftType := left.Type()
+		for i := 0; i < leftType.NumField(); i++ {
+			jsonName := leftType.Field(i).Tag.Get("json")
+			if jsonName == property {
+				property = leftType.Field(i).Name
+				break
+			}
+		}
+
+		fieldValue := left.FieldByNameFunc(func(name string) bool {
+			return strings.EqualFold(name, property)
+		})
+
+		if fieldValue.Kind() == reflect.Invalid {
+			return "", nil
+		}
+
+		return fieldValue.Interface(), nil
+
+	case reflect.Map:
+		iter := left.MapRange()
+
+		for iter.Next() {
+			key := iter.Key()
+
+			switch key.Kind() {
+			case reflect.String:
+				if strings.EqualFold(key.String(), property) {
+					return impl.getMapValue(iter.Value())
+				}
+
+			default:
+				return nil, fmt.Errorf("'%s' in map key not implemented", key.Kind())
+			}
+		}
+
+		return nil, fmt.Errorf("'%s' not found in '%s'", property, left.Type())
+
+	case reflect.Slice:
+		var values []interface{}
+
+		for i := 0; i < left.Len(); i++ {
+			value, err := impl.getPropertyValue(left.Index(i).Elem(), property)
+			if err != nil {
+				return nil, err
+			}
+
+			values = append(values, value)
+		}
+
+		return values, nil
+	}
+
+	return nil, fmt.Errorf("Unable to dereference '%s' on non-struct '%s'", property, left.Kind())
+}
+
+func (impl *interperterImpl) getMapValue(value reflect.Value) (interface{}, error) {
+	if value.Kind() == reflect.Ptr {
+		return impl.getMapValue(value.Elem())
+	}
+
+	return value.Interface(), nil
+}
+
+func (impl *interperterImpl) evaluateNot(notNode *actionlint.NotOpNode) (interface{}, error) {
+	operand, err := impl.evaluateNode(notNode.Operand)
+	if err != nil {
+		return nil, err
+	}
+
+	return !impl.isTruthy(reflect.ValueOf(operand)), nil
+}
+
+func (impl *interperterImpl) evaluateCompare(compareNode *actionlint.CompareOpNode) (interface{}, error) {
+	left, err := impl.evaluateNode(compareNode.Left)
+	if err != nil {
+		return nil, err
+	}
+
+	right, err := impl.evaluateNode(compareNode.Right)
+	if err != nil {
+		return nil, err
+	}
+
+	leftValue := reflect.ValueOf(left)
+	rightValue := reflect.ValueOf(right)
+
+	if leftValue.Kind() != rightValue.Kind() {
+		if !impl.isNumber(leftValue) {
+			leftValue = impl.coerceToNumber(leftValue)
+		}
+		if !impl.isNumber(rightValue) {
+			rightValue = impl.coerceToNumber(rightValue)
+		}
+	}
+
+	switch leftValue.Kind() {
+	case reflect.String:
+		return impl.compareString(strings.ToLower(leftValue.String()), strings.ToLower(rightValue.String()), compareNode.Kind)
+
+	case reflect.Int:
+		if rightValue.Kind() == reflect.Float64 {
+			return impl.compareNumber(float64(leftValue.Int()), rightValue.Float(), compareNode.Kind)
+		}
+
+		return impl.compareNumber(float64(leftValue.Int()), float64(rightValue.Int()), compareNode.Kind)
+
+	case reflect.Float64:
+		if rightValue.Kind() == reflect.Int {
+			return impl.compareNumber(leftValue.Float(), float64(rightValue.Int()), compareNode.Kind)
+		}
+
+		return impl.compareNumber(leftValue.Float(), rightValue.Float(), compareNode.Kind)
+
+	default:
+		return nil, fmt.Errorf("TODO: evaluateCompare not implemented %+v", reflect.TypeOf(left))
+	}
+}
+
+func (impl *interperterImpl) coerceToNumber(value reflect.Value) reflect.Value {
+	switch value.Kind() {
+	case reflect.Invalid:
+		return reflect.ValueOf(0)
+
+	case reflect.Bool:
+		switch value.Bool() {
+		case true:
+			return reflect.ValueOf(1)
+		case false:
+			return reflect.ValueOf(0)
+		}
+
+	case reflect.String:
+		if value.String() == "" {
+			return reflect.ValueOf(0)
+		}
+
+		// try to parse the string as a number
+		evaluated, err := impl.Evaluate(value.String(), false)
+		if err != nil {
+			return reflect.ValueOf(math.NaN())
+		}
+
+		if value := reflect.ValueOf(evaluated); impl.isNumber(value) {
+			return value
+		}
+	}
+
+	return reflect.ValueOf(math.NaN())
+}
+
+func (impl *interperterImpl) coerceToString(value reflect.Value) reflect.Value {
+	switch value.Kind() {
+	case reflect.Invalid:
+		return reflect.ValueOf("")
+
+	case reflect.Bool:
+		switch value.Bool() {
+		case true:
+			return reflect.ValueOf("true")
+		case false:
+			return reflect.ValueOf("false")
+		}
+
+	case reflect.String:
+		return value
+
+	case reflect.Int:
+		return reflect.ValueOf(fmt.Sprint(value))
+
+	case reflect.Float64:
+		if math.IsInf(value.Float(), 1) {
+			return reflect.ValueOf("Infinity")
+		} else if math.IsInf(value.Float(), -1) {
+			return reflect.ValueOf("-Infinity")
+		}
+		return reflect.ValueOf(fmt.Sprint(value))
+
+	case reflect.Slice:
+		return reflect.ValueOf("Array")
+
+	case reflect.Map:
+		return reflect.ValueOf("Object")
+	}
+
+	return value
+}
+
+func (impl *interperterImpl) compareString(left string, right string, kind actionlint.CompareOpNodeKind) (bool, error) {
+	switch kind {
+	case actionlint.CompareOpNodeKindLess:
+		return left < right, nil
+	case actionlint.CompareOpNodeKindLessEq:
+		return left <= right, nil
+	case actionlint.CompareOpNodeKindGreater:
+		return left > right, nil
+	case actionlint.CompareOpNodeKindGreaterEq:
+		return left >= right, nil
+	case actionlint.CompareOpNodeKindEq:
+		return left == right, nil
+	case actionlint.CompareOpNodeKindNotEq:
+		return left != right, nil
+	default:
+		return false, fmt.Errorf("TODO: not implemented to compare '%+v'", kind)
+	}
+}
+
+func (impl *interperterImpl) compareNumber(left float64, right float64, kind actionlint.CompareOpNodeKind) (bool, error) {
+	switch kind {
+	case actionlint.CompareOpNodeKindLess:
+		return left < right, nil
+	case actionlint.CompareOpNodeKindLessEq:
+		return left <= right, nil
+	case actionlint.CompareOpNodeKindGreater:
+		return left > right, nil
+	case actionlint.CompareOpNodeKindGreaterEq:
+		return left >= right, nil
+	case actionlint.CompareOpNodeKindEq:
+		return left == right, nil
+	case actionlint.CompareOpNodeKindNotEq:
+		return left != right, nil
+	default:
+		return false, fmt.Errorf("TODO: not implemented to compare '%+v'", kind)
+	}
+}
+
+func (impl *interperterImpl) isTruthy(value reflect.Value) bool {
+	switch value.Kind() {
+	case reflect.Bool:
+		return value.Bool()
+
+	case reflect.String:
+		return value.String() != ""
+
+	case reflect.Int:
+		return value.Int() != 0
+
+	case reflect.Float64:
+		if math.IsNaN(value.Float()) {
+			return false
+		}
+
+		return value.Float() != 0
+
+	case reflect.Map:
+		return true
+
+	case reflect.Slice:
+		return true
+
+	default:
+		return false
+	}
+}
+
+func (impl *interperterImpl) isNumber(value reflect.Value) bool {
+	switch value.Kind() {
+	case reflect.Int, reflect.Float64:
+		return true
+	default:
+		return false
+	}
+}
+
+func (impl *interperterImpl) getSafeValue(value reflect.Value) interface{} {
+	switch value.Kind() {
+	case reflect.Invalid:
+		return nil
+
+	case reflect.Float64:
+		if value.Float() == 0 {
+			return 0
+		}
+	}
+
+	return value.Interface()
+}
+
+func (impl *interperterImpl) evaluateLogicalCompare(compareNode *actionlint.LogicalOpNode) (interface{}, error) {
+	left, err := impl.evaluateNode(compareNode.Left)
+	if err != nil {
+		return nil, err
+	}
+
+	leftValue := reflect.ValueOf(left)
+
+	right, err := impl.evaluateNode(compareNode.Right)
+	if err != nil {
+		return nil, err
+	}
+
+	rightValue := reflect.ValueOf(right)
+
+	switch compareNode.Kind {
+	case actionlint.LogicalOpNodeKindAnd:
+		if impl.isTruthy(leftValue) {
+			return impl.getSafeValue(rightValue), nil
+		}
+
+		return impl.getSafeValue(leftValue), nil
+
+	case actionlint.LogicalOpNodeKindOr:
+		if impl.isTruthy(leftValue) {
+			return impl.getSafeValue(leftValue), nil
+		}
+
+		return impl.getSafeValue(rightValue), nil
+	}
+
+	return nil, fmt.Errorf("Unable to compare incompatibles types '%s' and '%s'", leftValue.Kind(), rightValue.Kind())
+}
+
+// nolint:gocyclo
+func (impl *interperterImpl) evaluateFuncCall(funcCallNode *actionlint.FuncCallNode) (interface{}, error) {
+	args := make([]reflect.Value, 0)
+
+	for _, arg := range funcCallNode.Args {
+		value, err := impl.evaluateNode(arg)
+		if err != nil {
+			return nil, err
+		}
+
+		args = append(args, reflect.ValueOf(value))
+	}
+
+	switch strings.ToLower(funcCallNode.Callee) {
+	case "contains":
+		return impl.contains(args[0], args[1])
+	case "startswith":
+		return impl.startsWith(args[0], args[1])
+	case "endswith":
+		return impl.endsWith(args[0], args[1])
+	case "format":
+		return impl.format(args[0], args[1:]...)
+	case "join":
+		if len(args) == 1 {
+			return impl.join(args[0], reflect.ValueOf(","))
+		}
+		return impl.join(args[0], args[1])
+	case "tojson":
+		return impl.toJSON(args[0])
+	case "fromjson":
+		return impl.fromJSON(args[0])
+	case "hashfiles":
+		return impl.hashFiles(args...)
+	case "always":
+		return impl.always()
+	case "success":
+		if impl.config.Context == "job" {
+			return impl.jobSuccess()
+		}
+		if impl.config.Context == "step" {
+			return impl.stepSuccess()
+		}
+		return nil, fmt.Errorf("Context '%s' must be one of 'job' or 'step'", impl.config.Context)
+	case "failure":
+		if impl.config.Context == "job" {
+			return impl.jobFailure()
+		}
+		if impl.config.Context == "step" {
+			return impl.stepFailure()
+		}
+		return nil, fmt.Errorf("Context '%s' must be one of 'job' or 'step'", impl.config.Context)
+	case "cancelled":
+		return impl.cancelled()
+	default:
+		return nil, fmt.Errorf("TODO: '%s' not implemented", funcCallNode.Callee)
+	}
+}
diff --git a/pkg/exprparser/interpreter_test.go b/pkg/exprparser/interpreter_test.go
new file mode 100644
index 00000000000..b17fee3b2ab
--- /dev/null
+++ b/pkg/exprparser/interpreter_test.go
@@ -0,0 +1,581 @@
+package exprparser
+
+import (
+	"math"
+	"testing"
+
+	"github.com/nektos/act/pkg/model"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLiterals(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"true", true, "true"},
+		{"false", false, "false"},
+		{"null", nil, "null"},
+		{"123", 123, "integer"},
+		{"-9.7", -9.7, "float"},
+		{"0xff", 255, "hex"},
+		{"-2.99e-2", -2.99e-2, "exponential"},
+		{"'foo'", "foo", "string"},
+		{"'it''s foo'", "it's foo", "string"},
+	}
+
+	env := &EvaluationEnvironment{}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestOperators(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+		error    string
+	}{
+		{"(false || (false || true))", true, "logical-grouping", ""},
+		{"github.action", "push", "property-dereference", ""},
+		{"github['action']", "push", "property-index", ""},
+		{"github.action[0]", nil, "string-index", "Unable to index on non-slice value: string"},
+		{"fromJSON('[0,1]')[1]", 1.0, "array-index", ""},
+		{"(github.event.commits.*.author.username)[0]", "someone", "array-index-0", ""},
+		{"!true", false, "not", ""},
+		{"1 < 2", true, "less-than", ""},
+		{`'b' <= 'a'`, false, "less-than-or-equal", ""},
+		{"1 > 2", false, "greater-than", ""},
+		{`'b' >= 'a'`, true, "greater-than-or-equal", ""},
+		{`'a' == 'a'`, true, "equal", ""},
+		{`'a' != 'a'`, false, "not-equal", ""},
+		{`true && false`, false, "and", ""},
+		{`true || false`, true, "or", ""},
+		{`fromJSON('{}') && true`, true, "and-boolean-object", ""},
+		{`fromJSON('{}') || false`, make(map[string]interface{}), "or-boolean-object", ""},
+	}
+
+	env := &EvaluationEnvironment{
+		Github: &model.GithubContext{
+			Action: "push",
+			Event: map[string]interface{}{
+				"commits": []interface{}{
+					map[string]interface{}{
+						"author": map[string]interface{}{
+							"username": "someone",
+						},
+					},
+					map[string]interface{}{
+						"author": map[string]interface{}{
+							"username": "someone-else",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			if tt.error != "" {
+				assert.NotNil(t, err)
+				assert.Equal(t, tt.error, err.Error())
+			} else {
+				assert.Nil(t, err)
+			}
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestOperatorsCompare(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"!null", true, "not-null"},
+		{"!-10", false, "not-neg-num"},
+		{"!0", true, "not-zero"},
+		{"!3.14", false, "not-pos-float"},
+		{"!''", true, "not-empty-str"},
+		{"!'abc'", false, "not-str"},
+		{"!fromJSON('{}')", false, "not-obj"},
+		{"!fromJSON('[]')", false, "not-arr"},
+		{`null == 0 }}`, true, "null-coercion"},
+		{`true == 1 }}`, true, "boolean-coercion"},
+		{`'' == 0 }}`, true, "string-0-coercion"},
+		{`'3' == 3 }}`, true, "string-3-coercion"},
+		{`0 == null }}`, true, "null-coercion-alt"},
+		{`1 == true }}`, true, "boolean-coercion-alt"},
+		{`0 == '' }}`, true, "string-0-coercion-alt"},
+		{`3 == '3' }}`, true, "string-3-coercion-alt"},
+		{`'TEST' == 'test' }}`, true, "string-casing"},
+		{`fromJSON('{}') < 2 }}`, false, "object-with-less"},
+		{`fromJSON('{}') < fromJSON('[]') }}`, false, "object/arr-with-lt"},
+		{`fromJSON('{}') > fromJSON('[]') }}`, false, "object/arr-with-gt"},
+	}
+
+	env := &EvaluationEnvironment{
+		Github: &model.GithubContext{
+			Action: "push",
+		},
+	}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
+
+func TestOperatorsBooleanEvaluation(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		// true &&
+		{"true && true", true, "true-and"},
+		{"true && false", false, "true-and"},
+		{"true && null", nil, "true-and"},
+		{"true && -10", -10, "true-and"},
+		{"true && 0", 0, "true-and"},
+		{"true && 10", 10, "true-and"},
+		{"true && 3.14", 3.14, "true-and"},
+		{"true && 0.0", 0, "true-and"},
+		{"true && Infinity", math.Inf(1), "true-and"},
+		// {"true && -Infinity", math.Inf(-1), "true-and"},
+		{"true && NaN", math.NaN(), "true-and"},
+		{"true && ''", "", "true-and"},
+		{"true && 'abc'", "abc", "true-and"},
+		// false &&
+		{"false && true", false, "false-and"},
+		{"false && false", false, "false-and"},
+		{"false && null", false, "false-and"},
+		{"false && -10", false, "false-and"},
+		{"false && 0", false, "false-and"},
+		{"false && 10", false, "false-and"},
+		{"false && 3.14", false, "false-and"},
+		{"false && 0.0", false, "false-and"},
+		{"false && Infinity", false, "false-and"},
+		// {"false && -Infinity", false, "false-and"},
+		{"false && NaN", false, "false-and"},
+		{"false && ''", false, "false-and"},
+		{"false && 'abc'", false, "false-and"},
+		// true ||
+		{"true || true", true, "true-or"},
+		{"true || false", true, "true-or"},
+		{"true || null", true, "true-or"},
+		{"true || -10", true, "true-or"},
+		{"true || 0", true, "true-or"},
+		{"true || 10", true, "true-or"},
+		{"true || 3.14", true, "true-or"},
+		{"true || 0.0", true, "true-or"},
+		{"true || Infinity", true, "true-or"},
+		// {"true || -Infinity", true, "true-or"},
+		{"true || NaN", true, "true-or"},
+		{"true || ''", true, "true-or"},
+		{"true || 'abc'", true, "true-or"},
+		// false ||
+		{"false || true", true, "false-or"},
+		{"false || false", false, "false-or"},
+		{"false || null", nil, "false-or"},
+		{"false || -10", -10, "false-or"},
+		{"false || 0", 0, "false-or"},
+		{"false || 10", 10, "false-or"},
+		{"false || 3.14", 3.14, "false-or"},
+		{"false || 0.0", 0, "false-or"},
+		{"false || Infinity", math.Inf(1), "false-or"},
+		// {"false || -Infinity", math.Inf(-1), "false-or"},
+		{"false || NaN", math.NaN(), "false-or"},
+		{"false || ''", "", "false-or"},
+		{"false || 'abc'", "abc", "false-or"},
+		// null &&
+		{"null && true", nil, "null-and"},
+		{"null && false", nil, "null-and"},
+		{"null && null", nil, "null-and"},
+		{"null && -10", nil, "null-and"},
+		{"null && 0", nil, "null-and"},
+		{"null && 10", nil, "null-and"},
+		{"null && 3.14", nil, "null-and"},
+		{"null && 0.0", nil, "null-and"},
+		{"null && Infinity", nil, "null-and"},
+		// {"null && -Infinity", nil, "null-and"},
+		{"null && NaN", nil, "null-and"},
+		{"null && ''", nil, "null-and"},
+		{"null && 'abc'", nil, "null-and"},
+		// null ||
+		{"null || true", true, "null-or"},
+		{"null || false", false, "null-or"},
+		{"null || null", nil, "null-or"},
+		{"null || -10", -10, "null-or"},
+		{"null || 0", 0, "null-or"},
+		{"null || 10", 10, "null-or"},
+		{"null || 3.14", 3.14, "null-or"},
+		{"null || 0.0", 0, "null-or"},
+		{"null || Infinity", math.Inf(1), "null-or"},
+		// {"null || -Infinity", math.Inf(-1), "null-or"},
+		{"null || NaN", math.NaN(), "null-or"},
+		{"null || ''", "", "null-or"},
+		{"null || 'abc'", "abc", "null-or"},
+		// -10 &&
+		{"-10 && true", true, "neg-num-and"},
+		{"-10 && false", false, "neg-num-and"},
+		{"-10 && null", nil, "neg-num-and"},
+		{"-10 && -10", -10, "neg-num-and"},
+		{"-10 && 0", 0, "neg-num-and"},
+		{"-10 && 10", 10, "neg-num-and"},
+		{"-10 && 3.14", 3.14, "neg-num-and"},
+		{"-10 && 0.0", 0, "neg-num-and"},
+		{"-10 && Infinity", math.Inf(1), "neg-num-and"},
+		// {"-10 && -Infinity", math.Inf(-1), "neg-num-and"},
+		{"-10 && NaN", math.NaN(), "neg-num-and"},
+		{"-10 && ''", "", "neg-num-and"},
+		{"-10 && 'abc'", "abc", "neg-num-and"},
+		// -10 ||
+		{"-10 || true", -10, "neg-num-or"},
+		{"-10 || false", -10, "neg-num-or"},
+		{"-10 || null", -10, "neg-num-or"},
+		{"-10 || -10", -10, "neg-num-or"},
+		{"-10 || 0", -10, "neg-num-or"},
+		{"-10 || 10", -10, "neg-num-or"},
+		{"-10 || 3.14", -10, "neg-num-or"},
+		{"-10 || 0.0", -10, "neg-num-or"},
+		{"-10 || Infinity", -10, "neg-num-or"},
+		// {"-10 || -Infinity", -10, "neg-num-or"},
+		{"-10 || NaN", -10, "neg-num-or"},
+		{"-10 || ''", -10, "neg-num-or"},
+		{"-10 || 'abc'", -10, "neg-num-or"},
+		// 0 &&
+		{"0 && true", 0, "zero-and"},
+		{"0 && false", 0, "zero-and"},
+		{"0 && null", 0, "zero-and"},
+		{"0 && -10", 0, "zero-and"},
+		{"0 && 0", 0, "zero-and"},
+		{"0 && 10", 0, "zero-and"},
+		{"0 && 3.14", 0, "zero-and"},
+		{"0 && 0.0", 0, "zero-and"},
+		{"0 && Infinity", 0, "zero-and"},
+		// {"0 && -Infinity", 0, "zero-and"},
+		{"0 && NaN", 0, "zero-and"},
+		{"0 && ''", 0, "zero-and"},
+		{"0 && 'abc'", 0, "zero-and"},
+		// 0 ||
+		{"0 || true", true, "zero-or"},
+		{"0 || false", false, "zero-or"},
+		{"0 || null", nil, "zero-or"},
+		{"0 || -10", -10, "zero-or"},
+		{"0 || 0", 0, "zero-or"},
+		{"0 || 10", 10, "zero-or"},
+		{"0 || 3.14", 3.14, "zero-or"},
+		{"0 || 0.0", 0, "zero-or"},
+		{"0 || Infinity", math.Inf(1), "zero-or"},
+		// {"0 || -Infinity", math.Inf(-1), "zero-or"},
+		{"0 || NaN", math.NaN(), "zero-or"},
+		{"0 || ''", "", "zero-or"},
+		{"0 || 'abc'", "abc", "zero-or"},
+		// 10 &&
+		{"10 && true", true, "pos-num-and"},
+		{"10 && false", false, "pos-num-and"},
+		{"10 && null", nil, "pos-num-and"},
+		{"10 && -10", -10, "pos-num-and"},
+		{"10 && 0", 0, "pos-num-and"},
+		{"10 && 10", 10, "pos-num-and"},
+		{"10 && 3.14", 3.14, "pos-num-and"},
+		{"10 && 0.0", 0, "pos-num-and"},
+		{"10 && Infinity", math.Inf(1), "pos-num-and"},
+		// {"10 && -Infinity", math.Inf(-1), "pos-num-and"},
+		{"10 && NaN", math.NaN(), "pos-num-and"},
+		{"10 && ''", "", "pos-num-and"},
+		{"10 && 'abc'", "abc", "pos-num-and"},
+		// 10 ||
+		{"10 || true", 10, "pos-num-or"},
+		{"10 || false", 10, "pos-num-or"},
+		{"10 || null", 10, "pos-num-or"},
+		{"10 || -10", 10, "pos-num-or"},
+		{"10 || 0", 10, "pos-num-or"},
+		{"10 || 10", 10, "pos-num-or"},
+		{"10 || 3.14", 10, "pos-num-or"},
+		{"10 || 0.0", 10, "pos-num-or"},
+		{"10 || Infinity", 10, "pos-num-or"},
+		// {"10 || -Infinity", 10, "pos-num-or"},
+		{"10 || NaN", 10, "pos-num-or"},
+		{"10 || ''", 10, "pos-num-or"},
+		{"10 || 'abc'", 10, "pos-num-or"},
+		// 3.14 &&
+		{"3.14 && true", true, "pos-float-and"},
+		{"3.14 && false", false, "pos-float-and"},
+		{"3.14 && null", nil, "pos-float-and"},
+		{"3.14 && -10", -10, "pos-float-and"},
+		{"3.14 && 0", 0, "pos-float-and"},
+		{"3.14 && 10", 10, "pos-float-and"},
+		{"3.14 && 3.14", 3.14, "pos-float-and"},
+		{"3.14 && 0.0", 0, "pos-float-and"},
+		{"3.14 && Infinity", math.Inf(1), "pos-float-and"},
+		// {"3.14 && -Infinity", math.Inf(-1), "pos-float-and"},
+		{"3.14 && NaN", math.NaN(), "pos-float-and"},
+		{"3.14 && ''", "", "pos-float-and"},
+		{"3.14 && 'abc'", "abc", "pos-float-and"},
+		// 3.14 ||
+		{"3.14 || true", 3.14, "pos-float-or"},
+		{"3.14 || false", 3.14, "pos-float-or"},
+		{"3.14 || null", 3.14, "pos-float-or"},
+		{"3.14 || -10", 3.14, "pos-float-or"},
+		{"3.14 || 0", 3.14, "pos-float-or"},
+		{"3.14 || 10", 3.14, "pos-float-or"},
+		{"3.14 || 3.14", 3.14, "pos-float-or"},
+		{"3.14 || 0.0", 3.14, "pos-float-or"},
+		{"3.14 || Infinity", 3.14, "pos-float-or"},
+		// {"3.14 || -Infinity", 3.14, "pos-float-or"},
+		{"3.14 || NaN", 3.14, "pos-float-or"},
+		{"3.14 || ''", 3.14, "pos-float-or"},
+		{"3.14 || 'abc'", 3.14, "pos-float-or"},
+		// Infinity &&
+		{"Infinity && true", true, "pos-inf-and"},
+		{"Infinity && false", false, "pos-inf-and"},
+		{"Infinity && null", nil, "pos-inf-and"},
+		{"Infinity && -10", -10, "pos-inf-and"},
+		{"Infinity && 0", 0, "pos-inf-and"},
+		{"Infinity && 10", 10, "pos-inf-and"},
+		{"Infinity && 3.14", 3.14, "pos-inf-and"},
+		{"Infinity && 0.0", 0, "pos-inf-and"},
+		{"Infinity && Infinity", math.Inf(1), "pos-inf-and"},
+		// {"Infinity && -Infinity", math.Inf(-1), "pos-inf-and"},
+		{"Infinity && NaN", math.NaN(), "pos-inf-and"},
+		{"Infinity && ''", "", "pos-inf-and"},
+		{"Infinity && 'abc'", "abc", "pos-inf-and"},
+		// Infinity ||
+		{"Infinity || true", math.Inf(1), "pos-inf-or"},
+		{"Infinity || false", math.Inf(1), "pos-inf-or"},
+		{"Infinity || null", math.Inf(1), "pos-inf-or"},
+		{"Infinity || -10", math.Inf(1), "pos-inf-or"},
+		{"Infinity || 0", math.Inf(1), "pos-inf-or"},
+		{"Infinity || 10", math.Inf(1), "pos-inf-or"},
+		{"Infinity || 3.14", math.Inf(1), "pos-inf-or"},
+		{"Infinity || 0.0", math.Inf(1), "pos-inf-or"},
+		{"Infinity || Infinity", math.Inf(1), "pos-inf-or"},
+		// {"Infinity || -Infinity", math.Inf(1), "pos-inf-or"},
+		{"Infinity || NaN", math.Inf(1), "pos-inf-or"},
+		{"Infinity || ''", math.Inf(1), "pos-inf-or"},
+		{"Infinity || 'abc'", math.Inf(1), "pos-inf-or"},
+		// -Infinity &&
+		// {"-Infinity && true", true, "neg-inf-and"},
+		// {"-Infinity && false", false, "neg-inf-and"},
+		// {"-Infinity && null", nil, "neg-inf-and"},
+		// {"-Infinity && -10", -10, "neg-inf-and"},
+		// {"-Infinity && 0", 0, "neg-inf-and"},
+		// {"-Infinity && 10", 10, "neg-inf-and"},
+		// {"-Infinity && 3.14", 3.14, "neg-inf-and"},
+		// {"-Infinity && 0.0", 0, "neg-inf-and"},
+		// {"-Infinity && Infinity", math.Inf(1), "neg-inf-and"},
+		// {"-Infinity && -Infinity", math.Inf(-1), "neg-inf-and"},
+		// {"-Infinity && NaN", math.NaN(), "neg-inf-and"},
+		// {"-Infinity && ''", "", "neg-inf-and"},
+		// {"-Infinity && 'abc'", "abc", "neg-inf-and"},
+		// -Infinity ||
+		// {"-Infinity || true", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || false", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || null", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || -10", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || 0", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || 10", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || 3.14", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || 0.0", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || Infinity", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || -Infinity", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || NaN", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || ''", math.Inf(-1), "neg-inf-or"},
+		// {"-Infinity || 'abc'", math.Inf(-1), "neg-inf-or"},
+		// NaN &&
+		{"NaN && true", math.NaN(), "nan-and"},
+		{"NaN && false", math.NaN(), "nan-and"},
+		{"NaN && null", math.NaN(), "nan-and"},
+		{"NaN && -10", math.NaN(), "nan-and"},
+		{"NaN && 0", math.NaN(), "nan-and"},
+		{"NaN && 10", math.NaN(), "nan-and"},
+		{"NaN && 3.14", math.NaN(), "nan-and"},
+		{"NaN && 0.0", math.NaN(), "nan-and"},
+		{"NaN && Infinity", math.NaN(), "nan-and"},
+		// {"NaN && -Infinity", math.NaN(), "nan-and"},
+		{"NaN && NaN", math.NaN(), "nan-and"},
+		{"NaN && ''", math.NaN(), "nan-and"},
+		{"NaN && 'abc'", math.NaN(), "nan-and"},
+		// NaN ||
+		{"NaN || true", true, "nan-or"},
+		{"NaN || false", false, "nan-or"},
+		{"NaN || null", nil, "nan-or"},
+		{"NaN || -10", -10, "nan-or"},
+		{"NaN || 0", 0, "nan-or"},
+		{"NaN || 10", 10, "nan-or"},
+		{"NaN || 3.14", 3.14, "nan-or"},
+		{"NaN || 0.0", 0, "nan-or"},
+		{"NaN || Infinity", math.Inf(1), "nan-or"},
+		// {"NaN || -Infinity", math.Inf(-1), "nan-or"},
+		{"NaN || NaN", math.NaN(), "nan-or"},
+		{"NaN || ''", "", "nan-or"},
+		{"NaN || 'abc'", "abc", "nan-or"},
+		// "" &&
+		{"'' && true", "", "empty-str-and"},
+		{"'' && false", "", "empty-str-and"},
+		{"'' && null", "", "empty-str-and"},
+		{"'' && -10", "", "empty-str-and"},
+		{"'' && 0", "", "empty-str-and"},
+		{"'' && 10", "", "empty-str-and"},
+		{"'' && 3.14", "", "empty-str-and"},
+		{"'' && 0.0", "", "empty-str-and"},
+		{"'' && Infinity", "", "empty-str-and"},
+		// {"'' && -Infinity", "", "empty-str-and"},
+		{"'' && NaN", "", "empty-str-and"},
+		{"'' && ''", "", "empty-str-and"},
+		{"'' && 'abc'", "", "empty-str-and"},
+		// "" ||
+		{"'' || true", true, "empty-str-or"},
+		{"'' || false", false, "empty-str-or"},
+		{"'' || null", nil, "empty-str-or"},
+		{"'' || -10", -10, "empty-str-or"},
+		{"'' || 0", 0, "empty-str-or"},
+		{"'' || 10", 10, "empty-str-or"},
+		{"'' || 3.14", 3.14, "empty-str-or"},
+		{"'' || 0.0", 0, "empty-str-or"},
+		{"'' || Infinity", math.Inf(1), "empty-str-or"},
+		// {"'' || -Infinity", math.Inf(-1), "empty-str-or"},
+		{"'' || NaN", math.NaN(), "empty-str-or"},
+		{"'' || ''", "", "empty-str-or"},
+		{"'' || 'abc'", "abc", "empty-str-or"},
+		// "abc" &&
+		{"'abc' && true", true, "str-and"},
+		{"'abc' && false", false, "str-and"},
+		{"'abc' && null", nil, "str-and"},
+		{"'abc' && -10", -10, "str-and"},
+		{"'abc' && 0", 0, "str-and"},
+		{"'abc' && 10", 10, "str-and"},
+		{"'abc' && 3.14", 3.14, "str-and"},
+		{"'abc' && 0.0", 0, "str-and"},
+		{"'abc' && Infinity", math.Inf(1), "str-and"},
+		// {"'abc' && -Infinity", math.Inf(-1), "str-and"},
+		{"'abc' && NaN", math.NaN(), "str-and"},
+		{"'abc' && ''", "", "str-and"},
+		{"'abc' && 'abc'", "abc", "str-and"},
+		// "abc" ||
+		{"'abc' || true", "abc", "str-or"},
+		{"'abc' || false", "abc", "str-or"},
+		{"'abc' || null", "abc", "str-or"},
+		{"'abc' || -10", "abc", "str-or"},
+		{"'abc' || 0", "abc", "str-or"},
+		{"'abc' || 10", "abc", "str-or"},
+		{"'abc' || 3.14", "abc", "str-or"},
+		{"'abc' || 0.0", "abc", "str-or"},
+		{"'abc' || Infinity", "abc", "str-or"},
+		// {"'abc' || -Infinity", "abc", "str-or"},
+		{"'abc' || NaN", "abc", "str-or"},
+		{"'abc' || ''", "abc", "str-or"},
+		{"'abc' || 'abc'", "abc", "str-or"},
+		// extra tests
+		{"0.0 && true", 0, "float-evaluation-0-alt"},
+		{"-1.5 && true", true, "float-evaluation-neg-alt"},
+	}
+
+	env := &EvaluationEnvironment{
+		Github: &model.GithubContext{
+			Action: "push",
+		},
+	}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			if expected, ok := tt.expected.(float64); ok && math.IsNaN(expected) {
+				assert.True(t, math.IsNaN(output.(float64)))
+			} else {
+				assert.Equal(t, tt.expected, output)
+			}
+		})
+	}
+}
+
+func TestContexts(t *testing.T) {
+	table := []struct {
+		input    string
+		expected interface{}
+		name     string
+	}{
+		{"github.action", "push", "github-context"},
+		{"env.TEST", "value", "env-context"},
+		{"job.status", "success", "job-context"},
+		{"steps.step-id.outputs.name", "value", "steps-context"},
+		{"runner.os", "Linux", "runner-context"},
+		{"secrets.name", "value", "secrets-context"},
+		{"strategy.fail-fast", true, "strategy-context"},
+		{"matrix.os", "Linux", "matrix-context"},
+		{"needs.job-id.outputs.output-name", "value", "needs-context"},
+		{"inputs.name", "value", "inputs-context"},
+	}
+
+	env := &EvaluationEnvironment{
+		Github: &model.GithubContext{
+			Action: "push",
+		},
+		Env: map[string]string{
+			"TEST": "value",
+		},
+		Job: &model.JobContext{
+			Status: "success",
+		},
+		Steps: map[string]*model.StepResult{
+			"step-id": {
+				Outputs: map[string]string{
+					"name": "value",
+				},
+			},
+		},
+		Runner: map[string]interface{}{
+			"os":         "Linux",
+			"temp":       "/tmp",
+			"tool_cache": "/opt/hostedtoolcache",
+		},
+		Secrets: map[string]string{
+			"name": "value",
+		},
+		Strategy: map[string]interface{}{
+			"fail-fast": true,
+		},
+		Matrix: map[string]interface{}{
+			"os": "Linux",
+		},
+		Needs: map[string]map[string]map[string]string{
+			"job-id": {
+				"outputs": {
+					"output-name": "value",
+				},
+			},
+		},
+		Inputs: map[string]string{
+			"name": "value",
+		},
+	}
+
+	for _, tt := range table {
+		t.Run(tt.name, func(t *testing.T) {
+			output, err := NewInterpeter(env, Config{}).Evaluate(tt.input, false)
+			assert.Nil(t, err)
+
+			assert.Equal(t, tt.expected, output)
+		})
+	}
+}
diff --git a/pkg/exprparser/testdata/for-hashing-1.txt b/pkg/exprparser/testdata/for-hashing-1.txt
new file mode 100644
index 00000000000..e965047ad7c
--- /dev/null
+++ b/pkg/exprparser/testdata/for-hashing-1.txt
@@ -0,0 +1 @@
+Hello
diff --git a/pkg/exprparser/testdata/for-hashing-2.txt b/pkg/exprparser/testdata/for-hashing-2.txt
new file mode 100644
index 00000000000..496c8755caf
--- /dev/null
+++ b/pkg/exprparser/testdata/for-hashing-2.txt
@@ -0,0 +1 @@
+World!