fileinfo: detect benchmark tests

modify our current parser to detect benchmark tests

Author: sluongng

language/go/fileinfo.go

@@ -61,6 +61,9 @@ type fileInfo struct {
 	// name ends with "_test"
 	isExternalTest bool
 
+	// hasBenchmarkTests is true if the file contains benchmark tests.
+	hasBenchmarkTests bool
+
 	// imports is a list of packages imported by a file. It does not include
 	// "C" or anything from the standard library.
 	imports []string
@@ -214,6 +217,7 @@ func otherFileInfo(path string) fileInfo {
 func goFileInfo(path, srcdir string) fileInfo {
 	info := fileNameInfo(path)
 	fset := token.NewFileSet()
+	// parse the file for imports and comments (for CGO)
 	pf, err := parser.ParseFile(fset, info.path, nil, parser.ImportsOnly|parser.ParseComments)
 	if err != nil {
 		log.Printf("%s: error reading go file: %v", info.path, err)
@@ -274,8 +278,8 @@ func goFileInfo(path, srcdir string) fileInfo {
 	}
 	info.tags = tags
 
-	if importsEmbed || info.packageName == "main" {
-		pf, err = parser.ParseFile(fset, info.path, nil, parser.ParseComments)
+	if importsEmbed || info.packageName == "main" || info.isTest {
+		pf, err = parser.ParseFile(fset, info.path, nil, parser.ParseComments|parser.SkipObjectResolution)
 		if err != nil {
 			log.Printf("%s: error reading go file: %v", info.path, err)
 			return info
@@ -309,6 +313,27 @@ func goFileInfo(path, srcdir string) fileInfo {
 				}
 			}
 		}
+		if info.isTest {
+			for _, decl := range pf.Decls {
+				fdecl, ok := decl.(*ast.FuncDecl)
+				if !ok || !strings.HasPrefix(fdecl.Name.Name, "Benchmark") || fdecl.Type.Params.NumFields() != 1 {
+					continue
+				}
+				// validate that the only param is of type *testing.B
+				starExpr, ok := fdecl.Type.Params.List[0].Type.(*ast.StarExpr)
+				if !ok {
+					continue
+				}
+				selector, ok := starExpr.X.(*ast.SelectorExpr)
+				if !ok || selector.Sel.String() != "B" {
+					continue
+				}
+				if pkgIdent, ok := selector.X.(*ast.Ident); ok && pkgIdent.Name == "testing" {
+					info.hasBenchmarkTests = true
+					break
+				}
+			}
+		}
 	}
 
 	return info

language/go/fileinfo_go_test.go

@@ -65,6 +65,66 @@ func TestGoFileInfo(t *testing.T) {
 				isTest:      false,
 			},
 		},
+		{
+			"hash bench test",
+			"foo_test.go",
+			`package foo_test
+
+func BenchmarkFoo(b *testing.B) {}`,
+			fileInfo{
+				packageName:       "foo",
+				isTest:            true,
+				hasBenchmarkTests: true,
+			},
+		},
+		{
+			"invalid bench test 1",
+			"foo_test.go",
+			`package foo_test
+
+func BenchmarkFoo(b *testing.B, a string) {}`,
+			fileInfo{
+				packageName:       "foo",
+				isTest:            true,
+				hasBenchmarkTests: false,
+			},
+		},
+		{
+			"invalid bench test 2",
+			"foo_test.go",
+			`package foo_test
+
+func CenchmarkFoo(b *testing.B) {}`,
+			fileInfo{
+				packageName:       "foo",
+				isTest:            true,
+				hasBenchmarkTests: false,
+			},
+		},
+		{
+			"invalid bench test 3",
+			"foo_test.go",
+			`package foo_test
+
+func BenchmarkFoo(b testing.B) {}`,
+			fileInfo{
+				packageName:       "foo",
+				isTest:            true,
+				hasBenchmarkTests: false,
+			},
+		},
+		{
+			"invalid bench test 4",
+			"foo_test.go",
+			`package foo_test
+
+func BenchmarkFoo(c *testing.C) {}`,
+			fileInfo{
+				packageName:       "foo",
+				isTest:            true,
+				hasBenchmarkTests: false,
+			},
+		},
 		{
 			"single import",
 			"foo.go",
@@ -183,12 +243,13 @@ var src string
 			got := goFileInfo(path, "")
 			// Clear fields we don't care about for testing.
 			got = fileInfo{
-				packageName: got.packageName,
-				isTest:      got.isTest,
-				imports:     got.imports,
-				embeds:      got.embeds,
-				isCgo:       got.isCgo,
-				tags:        got.tags,
+				packageName:       got.packageName,
+				isTest:            got.isTest,
+				imports:           got.imports,
+				embeds:            got.embeds,
+				isCgo:             got.isCgo,
+				tags:              got.tags,
+				hasBenchmarkTests: got.hasBenchmarkTests,
 			}
 			for i := range got.embeds {
 				got.embeds[i] = fileEmbed{path: got.embeds[i].path}