dev: new processor order (#5322)

Author: ldez

pkg/fsutils/fsutils.go

@@ -34,13 +34,13 @@ func Getwd() (string, error) {
 			return
 		}
 
-		evaledWd, err := EvalSymlinks(cachedWd)
+		evaluatedWd, err := EvalSymlinks(cachedWd)
 		if err != nil {
 			cachedWd, cachedWdError = "", fmt.Errorf("can't eval symlinks on wd %s: %w", cachedWd, err)
 			return
 		}
 
-		cachedWd = evaledWd
+		cachedWd = evaluatedWd
 	})
 
 	return cachedWd, cachedWdError
@@ -83,8 +83,8 @@ func ShortestRelPath(path, wd string) (string, error) {
 	path = evaledPath
 
 	// make path absolute and then relative to be able to fix this case:
-	// we are in /test dir, we want to normalize ../test, and have file file.go in this dir;
-	// it must have normalized path file.go, not ../test/file.go,
+	// we are in `/test` dir, we want to normalize `../test`, and have file `file.go` in this dir;
+	// it must have normalized path `file.go`, not `../test/file.go`,
 	var absPath string
 	if filepath.IsAbs(path) {
 		absPath = path

pkg/fsutils/fsutils_test.go

@@ -0,0 +1,42 @@
+package fsutils
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestShortestRelPath(t *testing.T) {
+	testCases := []struct {
+		desc     string
+		path     string
+		wd       string
+		expected string
+	}{
+		{
+			desc:     "based on parent path",
+			path:     "fsutils_test.go",
+			wd:       filepath.Join("..", "fsutils"),
+			expected: "fsutils_test.go",
+		},
+		{
+			desc:     "based on current working directory",
+			path:     "fsutils_test.go",
+			wd:       "",
+			expected: "fsutils_test.go",
+		},
+	}
+
+	for _, test := range testCases {
+		t.Run(test.desc, func(t *testing.T) {
+			t.Parallel()
+
+			rel, err := ShortestRelPath("fsutils_test.go", filepath.Join("..", "fsutils"))
+			require.NoError(t, err)
+
+			assert.Equal(t, test.expected, rel)
+		})
+	}
+}

pkg/lint/runner.go

@@ -79,10 +79,12 @@ func NewRunner(log logutils.Log, cfg *config.Config, args []string, goenv *gouti
 			// Must be after FilenameUnadjuster.
 			processors.NewInvalidIssue(log.Child(logutils.DebugKeyInvalidIssue)),
 
-			// Must be before diff, nolint and exclude autogenerated processor at least.
+			// Must be before Diff, SkipFiles, SkipDirs, ExcludeRules processors at least.
 			processors.NewPathPrettifier(log),
+
+			// must be after PathPrettifier.
 			skipFilesProcessor,
-			skipDirsProcessor, // must be after path prettifier
+			skipDirsProcessor,
 
 			processors.NewAutogeneratedExclude(cfg.Issues.ExcludeGenerated),
 
@@ -94,20 +96,21 @@ func NewRunner(log logutils.Log, cfg *config.Config, args []string, goenv *gouti
 
 			processors.NewNolint(log.Child(logutils.DebugKeyNolint), dbManager, enabledLinters),
 
-			processors.NewUniqByLine(cfg),
 			processors.NewDiff(&cfg.Issues),
+
+			// The fixer still needs to see paths for the issues that are relative to the current directory.
+			processors.NewFixer(cfg, log, fileCache, metaFormatter),
+
+			// Must be after the Fixer.
+			processors.NewUniqByLine(cfg),
 			processors.NewMaxPerFileFromLinter(cfg),
 			processors.NewMaxSameIssues(cfg.Issues.MaxSameIssues, log.Child(logutils.DebugKeyMaxSameIssues), cfg),
 			processors.NewMaxFromLinter(cfg.Issues.MaxIssuesPerLinter, log.Child(logutils.DebugKeyMaxFromLinter), cfg),
 
+			// Now we can modify the issues for output.
 			processors.NewSourceCode(lineCache, log.Child(logutils.DebugKeySourceCode)),
 			processors.NewPathShortener(),
 			processors.NewSeverity(log.Child(logutils.DebugKeySeverityRules), files, &cfg.Severity),
-
-			// The fixer still needs to see paths for the issues that are relative to the current directory.
-			processors.NewFixer(cfg, log, fileCache, metaFormatter),
-
-			// Now we can modify the issues for output.
 			processors.NewPathPrefixer(cfg.Output.PathPrefix),
 			processors.NewSortResults(cfg),
 		},

pkg/result/processors/autogenerated_exclude.go

@@ -39,6 +39,10 @@ type fileSummary struct {
 	generated bool
 }
 
+// AutogeneratedExclude filters generated files.
+//   - mode "lax": see `isGeneratedFileLax` documentation.
+//   - mode "strict": see `isGeneratedFileStrict` documentation.
+//   - mode "disable": skips this processor.
 type AutogeneratedExclude struct {
 	debugf logutils.DebugFunc
 

pkg/result/processors/cgo.go

@@ -10,10 +10,11 @@ import (
 
 var _ Processor = (*Cgo)(nil)
 
-// Cgo some linters (e.g. gosec, deadcode) return incorrect filepaths for cgo issues,
-// also cgo files have strange issues looking like false positives.
+// Cgo filters cgo artifacts.
 //
-// Require absolute filepath.
+// Some linters (e.g. gosec, etc.) return incorrect file paths for cgo files.
+//
+// Require absolute file path.
 type Cgo struct {
 	goCacheDir string
 }

pkg/result/processors/diff.go

@@ -18,6 +18,12 @@ const envGolangciDiffProcessorPatch = "GOLANGCI_DIFF_PROCESSOR_PATCH"
 
 var _ Processor = (*Diff)(nil)
 
+// Diff filters issues based on options `new`, `new-from-rev`, etc.
+//
+// Uses `git`.
+// The paths inside the patch are relative to the path where git is run (the same location where golangci-lint is run).
+//
+// Warning: it doesn't use `path-prefix` option.
 type Diff struct {
 	onlyNew       bool
 	fromRev       string

pkg/result/processors/exclude.go

@@ -11,6 +11,7 @@ import (
 
 var _ Processor = (*Exclude)(nil)
 
+// Exclude filters reports only based on regular expressions applied to the report text.
 type Exclude struct {
 	name string
 

pkg/result/processors/exclude_rules.go

@@ -15,6 +15,13 @@ type excludeRule struct {
 	baseRule
 }
 
+// ExcludeRules filters reports based on multiple criteria:
+//   - linter names (string)
+//   - file path (regular expressions)
+//   - text (regular expressions)
+//   - code source (regular expressions)
+//
+// It uses the shortest relative paths and `path-prefix` option.
 type ExcludeRules struct {
 	name string
 

pkg/result/processors/filename_unadjuster.go

@@ -22,11 +22,13 @@ type adjustMap struct {
 	m map[string]posMapper
 }
 
-// FilenameUnadjuster is needed because a lot of linters use `fset.Position(f.Pos())` to get filename.
-// And they return adjusted filename (e.g.` *.qtpl`) for an issue.
+// FilenameUnadjuster fixes filename based on adjusted and unadjusted position (related to line directives and cgo).
+//
+// A lot of linters use `fset.Position(f.Pos())` to get filename,
+// and they return adjusted filename (e.g.` *.qtpl`) for an issue.
 // We need restore real `.go` filename to properly output it, parse it, etc.
 //
-// Require absolute filepath.
+// Require absolute file path.
 type FilenameUnadjuster struct {
 	m                   map[string]posMapper // map from adjusted filename to position mapper: adjusted -> unadjusted position
 	log                 logutils.Log

pkg/result/processors/fixer.go

@@ -31,6 +31,8 @@ var _ Processor = (*Fixer)(nil)
 
 const filePerm = 0644
 
+// Fixer fixes reports if possible.
+// The reports that are not fixed are passed to the next processor.
 type Fixer struct {
 	cfg       *config.Config
 	log       logutils.Log