skip dirs without go files early: improve logs and save time

pkg/fsutils/path_resolver.go

@@ -184,5 +184,21 @@ func (pr PathResolver) Resolve(paths ...string) (*PathResolveResult, error) {
 		state.addFile(path)
 	}
 
+	state.excludeDirsWithoutGoFiles()
+
 	return state.toResult(), nil
 }
+
+func (s *pathResolveState) excludeDirsWithoutGoFiles() {
+	dirToFiles := map[string]bool{}
+	for f := range s.files {
+		dir := filepath.Dir(f)
+		dirToFiles[dir] = true
+	}
+
+	for dir := range s.dirs {
+		if !dirToFiles[dir] { // no go files in this dir
+			delete(s.dirs, dir)
+		}
+	}
+}

pkg/fsutils/path_resolver_test.go

@@ -84,30 +84,27 @@ func TestPathResolverCommonCases(t *testing.T) {
 		{
 			name:    "empty root recursively",
 			resolve: []string{"./..."},
-			expDirs: []string{"."},
 		},
 		{
 			name:    "empty root",
 			resolve: []string{"./"},
-			expDirs: []string{"."},
 		},
 		{
 			name:    "vendor is excluded recursively",
-			prepare: []string{"vendor/a/"},
+			prepare: []string{"vendor/a/b.go"},
 			resolve: []string{"./..."},
-			expDirs: []string{"."},
 		},
 		{
 			name:    "vendor is excluded",
-			prepare: []string{"vendor/"},
+			prepare: []string{"vendor/a.go"},
 			resolve: []string{"./..."},
-			expDirs: []string{"."},
 		},
 		{
-			name:    "vendor implicitely resolved",
-			prepare: []string{"vendor/"},
-			resolve: []string{"./vendor"},
-			expDirs: []string{"vendor"},
+			name:     "vendor implicitely resolved",
+			prepare:  []string{"vendor/a.go"},
+			resolve:  []string{"./vendor"},
+			expDirs:  []string{"vendor"},
+			expFiles: []string{"vendor/a.go"},
 		},
 		{
 			name:     "extensions filter recursively",
@@ -125,7 +122,7 @@ func TestPathResolverCommonCases(t *testing.T) {
 		},
 		{
 			name:     "one level dirs exclusion",
-			prepare:  []string{"a/b/", "a/c.go"},
+			prepare:  []string{"a/b/d.go", "a/c.go"},
 			resolve:  []string{"./a"},
 			expDirs:  []string{"a"},
 			expFiles: []string{"a/c.go"},
@@ -138,45 +135,58 @@ func TestPathResolverCommonCases(t *testing.T) {
 			expFiles: []string{"a/b/c.go", "a/d.txt"},
 		},
 		{
-			name:    ".* is always ignored",
+			name:    ".* dotfiles are always ignored",
 			prepare: []string{".git/a.go", ".circleci/b.go"},
 			resolve: []string{"./..."},
-			expDirs: []string{"."},
 		},
 		{
-			name:    "exclude dirs on any depth level",
-			prepare: []string{"ok/.git/a.go"},
-			resolve: []string{"./..."},
-			expDirs: []string{".", "ok"},
+			name:     "exclude dirs on any depth level",
+			prepare:  []string{"ok/.git/a.go", "ok/b.go"},
+			resolve:  []string{"./..."},
+			expDirs:  []string{"ok"},
+			expFiles: []string{"ok/b.go"},
 		},
 		{
 			name:    "ignore _*",
 			prepare: []string{"_any/a.go"},
 			resolve: []string{"./..."},
-			expDirs: []string{"."},
 		},
 		{
 			name:         "include tests",
 			prepare:      []string{"a/b.go", "a/b_test.go"},
 			resolve:      []string{"./..."},
-			expDirs:      []string{".", "a"},
+			expDirs:      []string{"a"},
 			expFiles:     []string{"a/b.go", "a/b_test.go"},
 			includeTests: true,
 		},
 		{
 			name:     "exclude tests",
 			prepare:  []string{"a/b.go", "a/b_test.go"},
 			resolve:  []string{"./..."},
-			expDirs:  []string{".", "a"},
+			expDirs:  []string{"a"},
 			expFiles: []string{"a/b.go"},
 		},
 		{
 			name:     "exclude tests except explicitly set",
 			prepare:  []string{"a/b.go", "a/b_test.go", "a/c_test.go"},
 			resolve:  []string{"./...", "a/c_test.go"},
-			expDirs:  []string{".", "a"},
+			expDirs:  []string{"a"},
 			expFiles: []string{"a/b.go", "a/c_test.go"},
 		},
+		{
+			name:     "exclude dirs with no go files",
+			prepare:  []string{"a/b.txt", "a/c/d.go"},
+			resolve:  []string{"./..."},
+			expDirs:  []string{"a/c"},
+			expFiles: []string{"a/c/d.go"},
+		},
+		{
+			name:     "exclude dirs with no go files with root dir",
+			prepare:  []string{"a/b.txt", "a/c/d.go", "e.go"},
+			resolve:  []string{"./..."},
+			expDirs:  []string{".", "a/c"},
+			expFiles: []string{"a/c/d.go", "e.go"},
+		},
 	}
 
 	for _, tc := range testCases {