test: check that fixer works with --path-prefix

The combination with --path gets tested for the first test case.
This is arbitrary. It could also be tested for all of them,
but then each test would have to run twice (with and without).

Author: pohly

test/fix_test.go

@@ -4,6 +4,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"sort"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -35,25 +36,42 @@ func TestFix(t *testing.T) {
 
 	sources := findSources(t, tmpDir, "in", "*.go")
 
-	for _, input := range sources {
+	// The combination with --path gets tested for the first test case.
+	// This is arbitrary. It could also be tested for all of them,
+	// but then each test would have to run twice (with and without).
+	// To make this determinstic, the sources get sorted by name.
+	sort.Strings(sources)
+
+	for i, input := range sources {
+		withPathPrefix := i == 0
 		input := input
 		t.Run(filepath.Base(input), func(t *testing.T) {
 			t.Parallel()
 
 			rc := testshared.ParseTestDirectives(t, input)
 			if rc == nil {
+				if withPathPrefix {
+					t.Errorf("The testcase %s should not get skipped, it's used for testing --path.", input)
+					return
+				}
 				t.Logf("Skipped: %s", input)
 				return
 			}
 
+			args := []string{
+				"--disable-all",
+				"--print-issued-lines=false",
+				"--print-linter-name=false",
+				"--out-format=line-number",
+				"--fix",
+			}
+			if withPathPrefix {
+				t.Log("Testing with --path-prefix.")
+				// This must not break fixing...
+				args = append(args, "--path-prefix=foobar/")
+			}
 			testshared.NewRunnerBuilder(t).
-				WithArgs(
-					"--disable-all",
-					"--print-issued-lines=false",
-					"--print-linter-name=false",
-					"--out-format=line-number",
-					"--fix",
-				).
+				WithArgs(args...).
 				WithRunContext(rc).
 				WithTargetPath(input).
 				Runner().