Adding "Compact Constants" Option

* Adding `CompactConstantDefinitions` boolean flag to `tables/tables.go`.
  * Can be set via tables json file (`--add_tables` / `--tables` command line or `tables` / `addTables` json config option).
* Updating `compactStmt()` in `build/print.go`.
  * If `CompactConstantDefinitions` is true and both statements are assignments (for const definitions), then the extra line should be removed.
  * Lower precedence than various other checks (like comment checks) to still allow extra lines when necessary.
* Updating `setFlags()` in `build/print_test.go`.
  * Checking golden filenames for ".compactconst." to set `CompactConstantDefinitions` to true.
  * Adding `CompactConstantDefinitions` reset back to false in returned (deferred) func.
* Copying various golden files (which contain constant definitions) to be ".compactconst." files.
  * Removing extra lines between const definitions as applicable.

Fixes bazelbuild#108.

build/print.go

@@ -277,6 +277,10 @@ func (p *printer) compactStmt(s1, s2 Expr) bool {
 		// Standalone comment blocks shouldn't be attached to other statements
 		return false
 	} else if (p.formattingMode() == TypeBuild) && p.level == 0 {
+		if tables.CompactConstantDefinitions && isAssignmentExpr(s1) && isAssignmentExpr(s2) {
+			// Two constant definitions do not need an extra line (if compact option enabled).
+			return true
+		}
 		// Top-level statements in a BUILD or WORKSPACE file
 		return false
 	} else if isFunctionDefinition(s1) || isFunctionDefinition(s2) {
@@ -446,6 +450,11 @@ func isCommentBlock(x Expr) bool {
 	return ok
 }
 
+func isAssignmentExpr(x Expr) bool {
+	_, ok := x.(*AssignExpr)
+	return ok
+}
+
 // isFunctionDefinition checks if the statement is a def code block
 func isFunctionDefinition(x Expr) bool {
 	_, ok := x.(*DefStmt)

build/print_test.go

@@ -45,9 +45,13 @@ func setFlags(file string) func() {
 	if strings.Contains(file, string(os.PathSeparator)+"050.") {
 		tables.ShortenAbsoluteLabelsToRelative = true
 	}
+	if strings.Contains(file, ".compactconst.") {
+		tables.CompactConstantDefinitions = true
+	}
 	return func() {
 		tables.StripLabelLeadingSlashes = false
 		tables.ShortenAbsoluteLabelsToRelative = false
+		tables.CompactConstantDefinitions = false
 	}
 }
 

build/testdata/004.compactconst.golden

@@ -0,0 +1,6 @@
+JAVA_FILES = [
+    "Foo.java",
+    "Bar.java",
+    "Baz.java",
+    "Quux.java",
+]

build/testdata/005.compactconst.golden

@@ -0,0 +1,7 @@
+JAVA_FILES = [
+    # Comment regarding Foo.java
+    "Foo.java",
+    "Bar.java",
+    "Baz.java",  # Comment regarding Baz.java
+    "Quux.java",
+]

build/testdata/006.compactconst.build.golden

@@ -0,0 +1,30 @@
+set = {
+    1,
+    2,
+    3,
+}
+multiline_set = {
+    4,
+    5,
+    [6],
+}
+plus = lambda x, y: x + y
+two = (lambda x: x(x))(lambda z: lambda y: z)(1)(2)(3)
+make_one = lambda: 1
+l = lambda x, y, *args, **kwargs: f(
+    y,
+    key = x,
+    *args,
+    **kwargs
+)
+
+TriggerActionAfterProbe(
+    action = lambda State, response: None,
+    predicate = lambda State, response: all([
+        response["request"]["method"] == "GET",
+        response["request"]["url"].find("/posts/") != -1,
+        response["request"]["url"].endswith("/comments"),
+        response["status_code"] in range(200, 299),
+    ]),
+    probe = ("http", "response"),
+)

build/testdata/006.compactconst.bzl.golden

@@ -0,0 +1,21 @@
+set = {1, 2, 3}
+multiline_set = {
+    4,
+    5,
+    [6],
+}
+plus = lambda x, y: x + y
+two = (lambda x: x(x))(lambda z: lambda y: z)(1)(2)(3)
+make_one = lambda: 1
+l = lambda x, y, *args, **kwargs: f(y, key = x, *args, **kwargs)
+
+TriggerActionAfterProbe(
+    probe = ("http", "response"),
+    predicate = lambda State, response: all([
+        response["request"]["method"] == "GET",
+        response["request"]["url"].find("/posts/") != -1,
+        response["request"]["url"].endswith("/comments"),
+        response["status_code"] in range(200, 299),
+    ]),
+    action = lambda State, response: None,
+)

build/testdata/017.compactconst.golden

@@ -0,0 +1,37 @@
+# c1
+greeting = "hello " + \
+           "world"  # c2
+# c3
+
+# c4
+greeting = "hello " + \
+           "world"  # c5
+# c6
+
+# c7
+greeting = "hello " + \
+           "world"  # c8
+# c9
+
+# c10
+greeting = ("hello " +  # c11
+            "world")  # c12
+# c13
+
+# c14
+greeting = ("hello " +  # c15
+            "world")  # c16
+# c17
+
+# c18
+greeting = ("hello" +  # c19
+            # c20
+            "world")  # c21
+# c22
+
+greeting = "hello " + \
+           "world"  # c23
+greeting = ("hello " +  # c24
+            "world")
+greeting = ("hello " +  # c25
+            "world")

build/testdata/043.compactconst.golden

@@ -0,0 +1,12 @@
+bar = "bar"
+
+# This gets an empty expr_opt in the parser, causing a nil to appear.
+b = bar[:-2]
+
+# Test that slices and partial slices are parsed properly
+f = foo[-1:-2:-3]
+f = foo[1::]
+f = foo[:1:]
+f = foo[::1]
+f = foo[::]
+f = foo[:]

build/testdata/066.compactconst.build.golden

@@ -0,0 +1,31 @@
+st1 = "abc"
+st2 = """
+multiline"""
+st3 = (
+    "multi"
+)
+n = 123
+id = a
+fct1 = foo(1)
+fct2 = foo(
+    arg = 1,
+)
+fct3 = (
+    foo(
+        arg = 1,
+    )
+)
+
+macro(
+    name = "foo",
+    arg = ["a"],
+)
+
+nested = 1
+comments = [
+    "a",
+    ("b"),  # end of line comment
+
+    # before comment
+    ("c"),
+]  # comment

build/testdata/066.compactconst.bzl.golden

@@ -0,0 +1,31 @@
+st1 = ("abc")
+st2 = ("""
+multiline""")
+st3 = (
+    "multi"
+)
+n = (123)
+id = (a)
+fct1 = (foo(1))
+fct2 = (foo(
+    arg = 1,
+))
+fct3 = (
+    foo(
+        arg = 1,
+    )
+)
+
+(macro(
+    name = ("foo"),
+    arg = ([("a")]),
+))
+
+nested = (((((1)))))
+comments = ([
+    "a",
+    ("b"),  # end of line comment
+
+    # before comment
+    ("c"),
+])  # comment

build/testdata/067.compactconst.build.golden

@@ -0,0 +1,53 @@
+load(
+    # A
+    "foo.bzl",
+    # B
+    "bar",
+)
+load(":a", "b")
+
+cc_binary(
+    # A
+    name = "bin",
+    # B
+    srcs = ["bin.cc"],
+    # C
+)
+
+cc_binary(
+    name = "wibble",
+    srcs = ["wibble.cc"],
+)
+
+my_list = [
+    1,
+    # A
+    2,
+    # B
+]
+my_1tuple = (
+    # A
+    1,
+    # B
+)
+my_2tuple = (
+    # A
+    1,
+    # B
+    2,
+    # C
+)
+my_dict = {
+    "a": 1,
+    # A
+    "b": 2,
+    # B
+}
+
+func(a)
+
+func(b)
+
+func(c, d)
+
+func(e, f)

build/testdata/067.compactconst.bzl.golden

@@ -0,0 +1,46 @@
+load(
+    # A
+    "foo.bzl",
+    # B
+    "bar",
+)
+load(":a", "b")
+
+cc_binary(
+    # A
+    name = "bin",
+    # B
+    srcs = ["bin.cc"],
+    # C
+)
+cc_binary(name = "wibble", srcs = ["wibble.cc"])
+
+my_list = [
+    1,
+    # A
+    2,
+    # B
+]
+my_1tuple = (
+    # A
+    1,
+    # B
+)
+my_2tuple = (
+    # A
+    1,
+    # B
+    2,
+    # C
+)
+my_dict = {
+    "a": 1,
+    # A
+    "b": 2,
+    # B
+}
+
+func(a)
+func(b)
+func(c, d)
+func(e, f)

tables/tables.go

@@ -209,6 +209,8 @@ var NamePriority = map[string]int{
 	"alwayslink":     7,
 }
 
+var CompactConstantDefinitions = false
+
 var StripLabelLeadingSlashes = false
 
 var ShortenAbsoluteLabelsToRelative = false