Exit Codes (#37)

README.md

@@ -30,6 +30,15 @@ Simply calling `codeowners` will kick off the cli on the current directory.
 | d             | .             | Directory: specifies the directory you want to use to lint the CODEOWNERS file |
 | f             |               | Format: specifies the format you want to return lint results                   |
 
+##### Exit Codes
+
+| Exit Code     | Description                                                      |
+| ------------- | ---------------------------------------------------------------- |
+| 0             | Success: no errors returned                                      |
+| 1             | Warnings: linter returned a few warnings but no errors           |
+| 2             | Errors: linter returned a few errors                             |
+| 3             | Unexpected errors: errors that prevented the linter from running |
+
 ## Compatibility
 
 :warning: This module is on a v0 mode and it is not ready to be used, once it reaches the v1 we will lock the API.

cmd/codeowners/linter.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"io"
 	"path/filepath"
 	"text/template"
@@ -14,33 +15,55 @@ type options struct {
 	format    string
 }
 
-func run(wr io.Writer, opt options) error {
+type exitCode int
+
+const (
+	successCode exitCode = iota
+	warningCode
+	errorCode
+	unexpectedErrorCode
+)
+
+func run(wr io.Writer, opt options) exitCode {
 	dir, err := filepath.Abs(opt.directory)
 	if err != nil {
-		return err
+		fmt.Fprintf(wr, "Unexpected error when parsing directory: %v", err)
+		return unexpectedErrorCode
 	}
 
-	format := "{{range .}}{{ .Position }} ::{{ .Severity }}:: {{ .Message }} [{{ .CheckName }}]\n{{end}}"
+	format := "{{ .Position }} ::{{ .Severity }}:: {{ .Message }} [{{ .CheckName }}]"
 	if len(opt.format) > 0 {
 		format = opt.format
 	}
+	format = fmt.Sprintf("%s\n", format)
 	tpl, err := template.New("main").Parse(format)
 	if err != nil {
-		return err
+		fmt.Fprintf(wr, "Unexpected error when parsing format: %v", err)
+		return unexpectedErrorCode
 	}
 
 	checkers := codeowners.AvailableCheckers()
 
 	checks, _ := codeowners.Check(dir, checkers...)
 
-	if len(checks) > 0 {
-		err = tpl.Execute(wr, checks)
+	code := successCode
+	for _, check := range checks {
+		err = tpl.Execute(wr, check)
 		if err != nil {
-			return err
+			fmt.Fprintf(wr, "Unexpected error when writing results: %v", err)
+			return unexpectedErrorCode
+		}
+		switch check.Severity {
+		case codeowners.Error:
+			if code < errorCode {
+				code = errorCode
+			}
+		case codeowners.Warning:
+			if code < warningCode {
+				code = warningCode
+			}
 		}
-	} else {
-		wr.Write([]byte("Everything ok ;)\n"))
 	}
 
-	return nil
+	return code
 }

cmd/codeowners/linter_test.go

@@ -5,104 +5,77 @@ import (
 	"testing"
 )
 
-func testRun(opt options) (string, error) {
+func testRun(opt options) (string, exitCode) {
 	var output bytes.Buffer
-	err := run(&output, opt)
-	if err != nil {
-		return "", err
-	}
-	return output.String(), nil
+	exitCode := run(&output, opt)
+	return output.String(), exitCode
 }
 
-func TestPass(t *testing.T) {
-	opt := options{
-		directory: "../../test/data/pass",
-		format:    "",
-	}
+func assertCode(t *testing.T, opt options, want exitCode) {
+	_, got := testRun(opt)
 
-	got, err := testRun(opt)
-	if err != nil {
-		t.Error(err)
+	if got != want {
+		t.Errorf("Input: %v Want: %d Got: %d", opt, want, got)
 	}
+}
 
-	want := `Everything ok ;)
-`
-	if got != want {
-		t.Errorf("Input: %v Want: '%s' Got: '%s'", opt, want, got)
+func assert(t *testing.T, opt options, wantCode exitCode, want string) {
+	got, gotCode := testRun(opt)
+
+	if gotCode != wantCode || got != want {
+		t.Errorf("Input: %v Want: %d '%s' Got: %d '%s'", opt, wantCode, want, gotCode, got)
 	}
 }
 
+func TestPass(t *testing.T) {
+	assertCode(t, options{
+		directory: "../../test/data/pass",
+		format:    "",
+	}, successCode)
+}
+
 func TestNoOwners(t *testing.T) {
-	opt := options{
+	assert(t, options{
 		directory: "../../test/data/no_owners",
 		format:    "",
-	}
-
-	got, err := testRun(opt)
-	if err != nil {
-		t.Error(err)
-	}
-
-	want := `1 ::Error:: No owners specified [NoOwner]
-`
-	if got != want {
-		t.Errorf("Input: %v Want: '%s' Got: '%s'", opt, want, got)
-	}
+	}, errorCode, `1 ::Error:: No owners specified [NoOwner]
+`)
 }
 
 func TestCustomFormat(t *testing.T) {
-	opt := options{
+	assert(t, options{
 		directory: "../../test/data/noowners",
 		format:    "test",
-	}
-
-	got, err := testRun(opt)
-	if err != nil {
-		t.Error(err)
-	}
-
-	want := `test`
-	if got != want {
-		t.Errorf("Input: %v Want: '%s' Got: '%s'", opt, want, got)
-	}
+	}, errorCode, `test
+`)
 }
 
-func TestInvalidFormat(t *testing.T) {
-	opt := options{
+func TestInvalidFormatParse(t *testing.T) {
+	assertCode(t, options{
 		directory: "../../test/data/noowners",
-		format:    "  {{template \"one\"}}  ",
-	}
-
-	_, err := testRun(opt)
-	if err == nil {
-		t.Errorf("Should have errored")
-	}
+		format:    "  {{template \"one ",
+	}, unexpectedErrorCode)
+}
 
-	opt = options{
+func TestInvalidFormatExec(t *testing.T) {
+	assertCode(t, options{
 		directory: "../../test/data/noowners",
-		format:    "  {{ . ",
-	}
-
-	_, err = testRun(opt)
-	if err == nil {
-		t.Errorf("Should have errored")
-	}
+		format:    "  {{template \"one\"}}  ",
+	}, unexpectedErrorCode)
 }
 
 func TestInvalidDirectory(t *testing.T) {
-	opt := options{
+	assert(t, options{
 		directory: "'",
 		format:    "",
-	}
-
-	got, err := testRun(opt)
-	if err != nil {
-		t.Error(err)
-	}
+	}, errorCode, `0 ::Error:: No CODEOWNERS file found [NoCodeowners]
+`)
+}
 
-	want := `0 ::Error:: No CODEOWNERS file found [NoCodeowners]
-`
-	if got != want {
-		t.Errorf("Input: %v Want: '%s' Got: '%s'", opt, want, got)
-	}
+func TestMultipleCodeOwners(t *testing.T) {
+	assert(t, options{
+		directory: "../../test/data/multiple_codeowners",
+		format:    "",
+	}, warningCode, `0 ::Warning:: Multiple CODEOWNERS files found (CODEOWNERS, docs/CODEOWNERS) [MultipleCodeowners]
+`)
 }

cmd/codeowners/main.go

@@ -4,7 +4,7 @@ package main
 
 import (
 	"flag"
-	"log"
+	"fmt"
 	"os"
 )
 
@@ -17,8 +17,10 @@ func main() {
 		directory: *dir,
 		format:    *format,
 	}
-
-	if err := run(os.Stdout, opt); err != nil {
-		log.Fatal(err)
+	exitCode := run(os.Stderr, opt)
+	if exitCode == successCode {
+		fmt.Println("Everything ok ;)")
+		return
 	}
+	os.Exit(int(exitCode))
 }