deb: auto-inject shlibs:depends and misc:depends

frontend/deb/template_control.go

@@ -4,6 +4,7 @@ import (
 	_ "embed"
 	"fmt"
 	"io"
+	"maps"
 	"strings"
 	"text/template"
 
@@ -57,13 +58,46 @@ func appendConstraints(deps map[string]dalec.PackageConstraints) []string {
 }
 
 func (w *controlWrapper) depends(buf io.Writer, depsSpec *dalec.PackageDependencies) {
-	if len(depsSpec.Runtime) == 0 {
-		return
+	var (
+		needsClone bool
+		rtDeps     map[string]dalec.PackageConstraints
+	)
+	if depsSpec == nil || depsSpec.Runtime == nil {
+		rtDeps = make(map[string]dalec.PackageConstraints)
+	} else {
+		rtDeps = depsSpec.Runtime
+		needsClone = true
 	}
 
-	deps := appendConstraints(depsSpec.Runtime)
-	fmt.Fprintln(buf, multiline("Depends", deps))
+	// Add in deps vars that will get resolved by debbuild
+	// In some cases these are not neccessary (maybe even most), but when they are
+	// it is important.
+	// When not needed lintian may throw warnings but that's ok.
+	// If these aren't actually needed they'll resolve to nothing and don't cause
+	// any changes.
+	const (
+		shlibsDeps = "${shlibs:Depends}"
+		miscDeps   = "${misc:Depends}"
+	)
+
+	if _, exists := rtDeps[shlibsDeps]; !exists {
+		if needsClone {
+			rtDeps = maps.Clone(rtDeps)
+			needsClone = false
+		}
+
+		rtDeps[shlibsDeps] = dalec.PackageConstraints{}
+	}
 
+	if _, exists := rtDeps[miscDeps]; !exists {
+		if needsClone {
+			rtDeps = maps.Clone(rtDeps)
+		}
+		rtDeps[miscDeps] = dalec.PackageConstraints{}
+	}
+
+	deps := appendConstraints(rtDeps)
+	fmt.Fprintln(buf, multiline("Depends", deps))
 }
 
 // multiline attempts to format a field with multiple values in a way that is more human readable

frontend/deb/template_rules_test.go

@@ -1,10 +1,13 @@
 package deb
 
 import (
+	"bytes"
+	"strings"
 	"testing"
 
 	"github.com/Azure/dalec"
 	"gotest.tools/v3/assert"
+	"gotest.tools/v3/assert/cmp"
 )
 
 func TestRules_OverrideSystemd(t *testing.T) {
@@ -109,3 +112,81 @@ func TestRules_OverrideSystemd(t *testing.T) {
 		})
 	})
 }
+
+func TestDepends(t *testing.T) {
+	control := &controlWrapper{}
+
+	buf := bytes.NewBuffer(nil)
+	control.depends(buf, nil)
+
+	expect := `
+Depends: ${misc:Depends},
+         ${shlibs:Depends}
+`
+	actual := strings.TrimSpace(buf.String())
+	assert.Check(t, cmp.Equal(actual, strings.TrimSpace(expect)))
+
+	buf.Reset()
+
+	// Test again with non-nil deps
+	control.depends(buf, &dalec.PackageDependencies{})
+	actual = strings.TrimSpace(buf.String())
+	assert.Check(t, cmp.Equal(actual, strings.TrimSpace(expect)))
+
+	buf.Reset()
+
+	// Test again with non-nil runtime deps
+	control.depends(buf, &dalec.PackageDependencies{
+		Runtime: map[string]dalec.PackageConstraints{},
+	})
+	actual = strings.TrimSpace(buf.String())
+	assert.Check(t, cmp.Equal(actual, strings.TrimSpace(expect)))
+
+	buf.Reset()
+
+	// Test again with other runtime deps
+	control.depends(buf, &dalec.PackageDependencies{
+		Runtime: map[string]dalec.PackageConstraints{
+			"foo": {},
+			"bar": {},
+		},
+	})
+
+	expect = `
+Depends: ${misc:Depends},
+         ${shlibs:Depends},
+         bar,
+         foo
+`
+	actual = strings.TrimSpace(buf.String())
+	assert.Check(t, cmp.Equal(actual, strings.TrimSpace(expect)))
+
+	buf.Reset()
+
+	// Test again with other runtime deps and shlibs specified
+	control.depends(buf, &dalec.PackageDependencies{
+		Runtime: map[string]dalec.PackageConstraints{
+			"foo":               {},
+			"bar":               {},
+			"${shlibs:Depends}": {},
+		},
+	})
+
+	actual = strings.TrimSpace(buf.String())
+	assert.Check(t, cmp.Equal(actual, strings.TrimSpace(expect)))
+
+	buf.Reset()
+
+	// Test again with other runtime deps and shlibs and misc depends specified
+	control.depends(buf, &dalec.PackageDependencies{
+		Runtime: map[string]dalec.PackageConstraints{
+			"foo":               {},
+			"bar":               {},
+			"${shlibs:Depends}": {},
+			"${misc:Depends}":   {},
+		},
+	})
+
+	actual = strings.TrimSpace(buf.String())
+	assert.Check(t, cmp.Equal(actual, strings.TrimSpace(expect)))
+}