per-rule file exclude filters (#850) (#857)

README.md

@@ -425,6 +425,37 @@ warningCode = 0
 [rule.redefines-builtin-id]
 ```
 
+### Rule-level file excludes
+
+You also can setup custom excludes for each rule.
+
+It's alternative for global `-exclude` program arg.
+
+```toml
+ignoreGeneratedHeader = false
+severity = "warning"
+confidence = 0.8
+errorCode = 0
+warningCode = 0
+
+[rule.blank-imports]
+   Exclude=["**/*.pb.go"]
+[rule.context-as-argument]
+   Exclude=["src/somepkg/*.go", "TEST"]
+```
+
+You can use following exclude patterns
+
+1. full paths to files `src/pkg/mypkg/some.go`
+2. globs `src/**/*.pb.go`
+3. regexes (should have prefix ~) `~\.(pb|auto|generated)\.go$`
+4. well-known `TEST` (same as `**/*_test.go`)
+5. special cases:
+  a. `*` and `~` patterns exclude all files (same effect than disabling the rule)
+  b. `""` (empty) pattern excludes nothing
+
+> NOTE: do not mess with `exclude` that can  be used at top level of TOML file, that mean "exclude package patterns", not "exclude file patterns"
+
 ## Available Rules
 
 List of all available rules. The rules ported from `golint` are left unchanged and indicated in the `golint` column.

config/config.go

@@ -149,6 +149,14 @@ func parseConfig(path string, config *lint.Config) error {
 	if err != nil {
 		return fmt.Errorf("cannot parse the config file: %v", err)
 	}
+	for k, r := range config.Rules {
+		err := r.Initialize()
+		if err != nil {
+			return fmt.Errorf("error in config of rule [%s] : [%v]", k, err)
+		}
+		config.Rules[k] = r
+	}
+
 	return nil
 }
 

config/config_test.go

@@ -61,6 +61,27 @@ func TestGetConfig(t *testing.T) {
 			}
 		})
 	}
+
+	t.Run("rule-level file filter excludes", func(t *testing.T) {
+		cfg, err := GetConfig("testdata/rule-level-exclude-850.toml")
+		if err != nil {
+			t.Fatal("should be valid config")
+		}
+		r1 := cfg.Rules["r1"]
+		if len(r1.Exclude) > 0 {
+			t.Fatal("r1 should have empty excludes")
+		}
+		r2 := cfg.Rules["r2"]
+		if len(r2.Exclude) != 1 {
+			t.Fatal("r2 should have exclude set")
+		}
+		if !r2.MustExclude("some/file.go") {
+			t.Fatal("r2 should be initialized and exclude some/file.go")
+		}
+		if r2.MustExclude("some/any-other.go") {
+			t.Fatal("r2 should not exclude some/any-other.go")
+		}
+	})
 }
 
 func TestGetLintingRules(t *testing.T) {

config/testdata/rule-level-exclude-850.toml

@@ -0,0 +1,13 @@
+ignoreGeneratedHeader = false
+severity = "warning"
+confidence = 0.8
+errorCode = 0
+warningCode = 0
+
+enableAllRules = false
+
+[rule.r1]
+    # no excludes
+
+[rule.r2]
+    exclude=["some/file.go"]

lint/config.go

@@ -3,16 +3,44 @@ package lint
 // Arguments is type used for the arguments of a rule.
 type Arguments = []interface{}
 
+type FileFilters = []*FileFilter
+
 // RuleConfig is type used for the rule configuration.
 type RuleConfig struct {
 	Arguments Arguments
 	Severity  Severity
 	Disabled  bool
+	// Exclude - rule-level file excludes, TOML related (strings)
+	Exclude []string
+	// excludeFilters - regex-based file filters, initialized from Exclude
+	excludeFilters []*FileFilter
+}
+
+// Initialize - should be called after reading from TOML file
+func (rc *RuleConfig) Initialize() error {
+	for _, f := range rc.Exclude {
+		ff, err := ParseFileFilter(f)
+		if err != nil {
+			return err
+		}
+		rc.excludeFilters = append(rc.excludeFilters, ff)
+	}
+	return nil
 }
 
 // RulesConfig defines the config for all rules.
 type RulesConfig = map[string]RuleConfig
 
+// MustExclude - checks if given filename `name` must be excluded
+func (rcfg *RuleConfig) MustExclude(name string) bool {
+	for _, exclude := range rcfg.excludeFilters {
+		if exclude.MatchFileName(name) {
+			return true
+		}
+	}
+	return false
+}
+
 // DirectiveConfig is type used for the linter directive configuration.
 type DirectiveConfig struct {
 	Severity Severity

lint/file.go

@@ -102,6 +102,9 @@ func (f *File) lint(rules []Rule, config Config, failures chan Failure) {
 	disabledIntervals := f.disabledIntervals(rules, mustSpecifyDisableReason, failures)
 	for _, currentRule := range rules {
 		ruleConfig := rulesConfig[currentRule.Name()]
+		if ruleConfig.MustExclude(f.Name) {
+			continue
+		}
 		currentFailures := currentRule.Apply(f, ruleConfig.Arguments)
 		for idx, failure := range currentFailures {
 			if failure.RuleName == "" {

lint/filefilter.go

@@ -0,0 +1,128 @@
+package lint
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+// FileFilter - file filter to exclude some files for rule
+// supports whole
+// 1. file/dir names : pkg/mypkg/my.go,
+// 2. globs: **/*.pb.go,
+// 3. regexes (~ prefix) ~-tmp\.\d+\.go
+// 4. special test marker `TEST` - treats as `~_test\.go`
+type FileFilter struct {
+	// raw definition of filter inside config
+	raw string
+	// don't care what was at start, will use regexes inside
+	rx *regexp.Regexp
+	// marks filter as matching everything
+	matchesAll bool
+	// marks filter as matching nothing
+	matchesNothing bool
+}
+
+// ParseFileFilter - creates [FileFilter] for given raw filter
+// if empty string, it matches nothing
+// if `*`, or `~`, it matches everything
+// while regexp could be invalid, it could return it's compilation error
+func ParseFileFilter(rawFilter string) (*FileFilter, error) {
+	rawFilter = strings.TrimSpace(rawFilter)
+	result := new(FileFilter)
+	result.raw = rawFilter
+	result.matchesNothing = len(result.raw) == 0
+	result.matchesAll = result.raw == "*" || result.raw == "~"
+	if !result.matchesAll && !result.matchesNothing {
+		if err := result.prepareRegexp(); err != nil {
+			return nil, err
+		}
+	}
+	return result, nil
+}
+
+func (ff *FileFilter) String() string { return ff.raw }
+
+// MatchFileName - checks if file name matches filter
+func (ff *FileFilter) MatchFileName(name string) bool {
+	if ff.matchesAll {
+		return true
+	}
+	if ff.matchesNothing {
+		return false
+	}
+	name = strings.ReplaceAll(name, "\\", "/")
+	return ff.rx.MatchString(name)
+}
+
+var fileFilterInvalidGlobRegexp = regexp.MustCompile(`[^/]\*\*[^/]`)
+var escapeRegexSymbols = ".+{}()[]^$"
+
+func (ff *FileFilter) prepareRegexp() error {
+	var err error
+	var src = ff.raw
+	if src == "TEST" {
+		src = "~_test\\.go"
+	}
+	if strings.HasPrefix(src, "~") {
+		ff.rx, err = regexp.Compile(src[1:])
+		if err != nil {
+			return fmt.Errorf("invalid file filter [%s], regexp compile error: [%v]", ff.raw, err)
+		}
+		return nil
+	}
+	/* globs */
+	if strings.Contains(src, "*") {
+		if fileFilterInvalidGlobRegexp.MatchString(src) {
+			return fmt.Errorf("invalid file filter [%s], invalid glob pattern", ff.raw)
+		}
+		var rxBuild strings.Builder
+		rxBuild.WriteByte('^')
+		wasStar := false
+		justDirGlob := false
+		for _, c := range src {
+			if c == '*' {
+				if wasStar {
+					rxBuild.WriteString(`[\s\S]*`)
+					wasStar = false
+					justDirGlob = true
+					continue
+				}
+				wasStar = true
+				continue
+			}
+			if wasStar {
+				rxBuild.WriteString("[^/]*")
+				wasStar = false
+			}
+			if strings.ContainsRune(escapeRegexSymbols, c) {
+				rxBuild.WriteByte('\\')
+			}
+			rxBuild.WriteRune(c)
+			if c == '/' && justDirGlob {
+				rxBuild.WriteRune('?')
+			}
+			justDirGlob = false
+		}
+		if wasStar {
+			rxBuild.WriteString("[^/]*")
+		}
+		rxBuild.WriteByte('$')
+		ff.rx, err = regexp.Compile(rxBuild.String())
+		if err != nil {
+			return fmt.Errorf("invalid file filter [%s], regexp compile error after glob expand: [%v]", ff.raw, err)
+		}
+		return nil
+	}
+
+	// it's whole file mask, just escape dots and normilze separators
+	fillRx := src
+	fillRx = strings.ReplaceAll(fillRx, "\\", "/")
+	fillRx = strings.ReplaceAll(fillRx, ".", `\.`)
+	fillRx = "^" + fillRx + "$"
+	ff.rx, err = regexp.Compile(fillRx)
+	if err != nil {
+		return fmt.Errorf("invalid file filter [%s], regexp compile full path: [%v]", ff.raw, err)
+	}
+	return nil
+}

lint/filefilter_test.go

@@ -0,0 +1,128 @@
+package lint_test
+
+import (
+	"testing"
+
+	"github.com/mgechev/revive/lint"
+)
+
+func TestFileFilter(t *testing.T) {
+	t.Run("whole file name", func(t *testing.T) {
+		ff, err := lint.ParseFileFilter("a/b/c.go")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !ff.MatchFileName("a/b/c.go") {
+			t.Fatal("should match a/b/c.go")
+		}
+		if ff.MatchFileName("a/b/d.go") {
+			t.Fatal("should not match")
+		}
+	})
+
+	t.Run("regex", func(t *testing.T) {
+		ff, err := lint.ParseFileFilter("~b/[cd].go$")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !ff.MatchFileName("a/b/c.go") {
+			t.Fatal("should match a/b/c.go")
+		}
+		if !ff.MatchFileName("b/d.go") {
+			t.Fatal("should match b/d.go")
+		}
+		if ff.MatchFileName("b/x.go") {
+			t.Fatal("should not match b/x.go")
+		}
+	})
+
+	t.Run("TEST well-known", func(t *testing.T) {
+		ff, err := lint.ParseFileFilter("TEST")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !ff.MatchFileName("a/b/c_test.go") {
+			t.Fatal("should match a/b/c_test.go")
+		}
+		if ff.MatchFileName("a/b/c_test_no.go") {
+			t.Fatal("should not match a/b/c_test_no.go")
+		}
+	})
+
+	t.Run("glob *", func(t *testing.T) {
+		ff, err := lint.ParseFileFilter("a/b/*.pb.go")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !ff.MatchFileName("a/b/xxx.pb.go") {
+			t.Fatal("should match a/b/xxx.pb.go")
+		}
+		if !ff.MatchFileName("a/b/yyy.pb.go") {
+			t.Fatal("should match a/b/yyy.pb.go")
+		}
+		if ff.MatchFileName("a/b/xxx.nopb.go") {
+			t.Fatal("should not match a/b/xxx.nopb.go")
+		}
+	})
+
+	t.Run("glob **", func(t *testing.T) {
+		ff, err := lint.ParseFileFilter("a/**/*.pb.go")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !ff.MatchFileName("a/x/xxx.pb.go") {
+			t.Fatal("should match a/x/xxx.pb.go")
+		}
+		if !ff.MatchFileName("a/xxx.pb.go") {
+			t.Fatal("should match a/xxx.pb.go")
+		}
+		if !ff.MatchFileName("a/x/y/z/yyy.pb.go") {
+			t.Fatal("should match a/x/y/z/yyy.pb.go")
+		}
+		if ff.MatchFileName("a/b/xxx.nopb.go") {
+			t.Fatal("should not match a/b/xxx.nopb.go")
+		}
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		ff, err := lint.ParseFileFilter("")
+		if err != nil {
+			t.Fatal(err)
+		}
+		fileNames := []string{"pb.go", "a/pb.go", "a/x/xxx.pb.go", "a/x/xxx.pb_test.go"}
+		for _, fn := range fileNames {
+			if ff.MatchFileName(fn) {
+				t.Fatalf("should not match %s", fn)
+			}
+		}
+
+	})
+
+	t.Run("just *", func(t *testing.T) {
+		ff, err := lint.ParseFileFilter("*")
+		if err != nil {
+			t.Fatal(err)
+		}
+		fileNames := []string{"pb.go", "a/pb.go", "a/x/xxx.pb.go", "a/x/xxx.pb_test.go"}
+		for _, fn := range fileNames {
+			if !ff.MatchFileName(fn) {
+				t.Fatalf("should match %s", fn)
+			}
+		}
+
+	})
+
+	t.Run("just ~", func(t *testing.T) {
+		ff, err := lint.ParseFileFilter("~")
+		if err != nil {
+			t.Fatal(err)
+		}
+		fileNames := []string{"pb.go", "a/pb.go", "a/x/xxx.pb.go", "a/x/xxx.pb_test.go"}
+		for _, fn := range fileNames {
+			if !ff.MatchFileName(fn) {
+				t.Fatalf("should match %s", fn)
+			}
+		}
+
+	})
+}

test/file-filter_test.go

@@ -0,0 +1,48 @@
+package test
+
+import (
+	"testing"
+
+	"github.com/mgechev/revive/lint"
+)
+
+type TestFileFilterRule struct {
+	WasApplyed bool
+}
+
+var _ lint.Rule = (*TestFileFilterRule)(nil)
+
+func (*TestFileFilterRule) Name() string { return "test-file-filter" }
+func (tfr *TestFileFilterRule) Apply(*lint.File, lint.Arguments) []lint.Failure {
+	tfr.WasApplyed = true
+	return nil
+}
+
+func TestFileExcludeFilterAtRuleLevel(t *testing.T) {
+	t.Run("is called if no excludes", func(t *testing.T) {
+		rule := &TestFileFilterRule{}
+		testRule(t, "file-to-exclude", rule, &lint.RuleConfig{})
+		if !rule.WasApplyed {
+			t.Fatal("should call rule if no excludes")
+		}
+	})
+	t.Run("is called if exclude not match", func(t *testing.T) {
+		rule := &TestFileFilterRule{}
+		cfg := &lint.RuleConfig{Exclude: []string{"no-matched.go"}}
+		cfg.Initialize()
+		testRule(t, "file-to-exclude", rule, cfg)
+		if !rule.WasApplyed {
+			t.Fatal("should call rule if no excludes")
+		}
+	})
+
+	t.Run("not called if exclude not match", func(t *testing.T) {
+		rule := &TestFileFilterRule{}
+		cfg := &lint.RuleConfig{Exclude: []string{"file-to-exclude.go"}}
+		cfg.Initialize()
+		testRule(t, "file-to-exclude", rule, cfg)
+		if rule.WasApplyed {
+			t.Fatal("should not call rule if excluded")
+		}
+	})
+}

testdata/file-to-exclude.go

@@ -0,0 +1,2 @@
+// just to check FileFilter
+package fixtures