Adding -update test flag for golden files

analyzer_test.go

@@ -18,8 +18,9 @@ func TestDeriveManifestAndLock(t *testing.T) {
 	defer h.Cleanup()
 
 	h.TempDir("dep")
-	contents := h.GetTestFileString("analyzer/manifest.json")
-	h.TempCopy(filepath.Join("dep", ManifestName), "analyzer/manifest.json")
+	golden := "analyzer/manifest.json"
+	contents := h.GetTestFileString(golden)
+	h.TempCopy(filepath.Join("dep", ManifestName), golden)
 
 	a := analyzer{}
 
@@ -34,7 +35,13 @@ func TestDeriveManifestAndLock(t *testing.T) {
 	}
 
 	if contents != string(b) {
-		t.Fatalf("expected %s\n got %s", contents, string(b))
+		if *test.UpdateGolden {
+			if err := h.WriteTestFile(golden, string(b)); err != nil {
+				t.Fatal(err)
+			}
+		} else {
+			t.Fatalf("expected %s\n got %s", contents, string(b))
+		}
 	}
 
 	if l != nil {

fs_test.go

@@ -129,7 +129,7 @@ func TestIsRegular(t *testing.T) {
 
 	tests := map[string]bool{
 		wd: false,
-		filepath.Join(wd, "_testdata"):                      false,
+		filepath.Join(wd, "testdata"):                       false,
 		filepath.Join(wd, "cmd", "dep", "main.go"):          true,
 		filepath.Join(wd, "this_file_does_not_exist.thing"): false,
 	}
@@ -160,7 +160,7 @@ func TestIsDir(t *testing.T) {
 
 	tests := map[string]bool{
 		wd: true,
-		filepath.Join(wd, "_testdata"):                      true,
+		filepath.Join(wd, "testdata"):                       true,
 		filepath.Join(wd, "main.go"):                        false,
 		filepath.Join(wd, "this_file_does_not_exist.thing"): false,
 	}

lock_test.go

@@ -25,7 +25,8 @@ func TestReadLock(t *testing.T) {
 		t.Errorf("Unexpected error %q; expected multiple version error", err)
 	}
 
-	l, err := readLock(h.GetTestFile("lock/golden.json"))
+	golden := "lock/golden.json"
+	l, err := readLock(h.GetTestFile(golden))
 	if err != nil {
 		t.Fatalf("Should have read Lock correctly, but got err %q", err)
 	}
@@ -44,6 +45,7 @@ func TestReadLock(t *testing.T) {
 
 	if !reflect.DeepEqual(l, l2) {
 		t.Error("Valid lock did not parse as expected")
+
 	}
 }
 
@@ -51,7 +53,8 @@ func TestWriteLock(t *testing.T) {
 	h := test.NewHelper(t)
 	defer h.Cleanup()
 
-	lg := h.GetTestFileString("lock/golden.json")
+	golden := "lock/golden.json"
+	lg := h.GetTestFileString(golden)
 	memo, _ := hex.DecodeString("2252a285ab27944a4d7adcba8dbd03980f59ba652f12db39fa93b927c345593e")
 	l := &Lock{
 		Memo: memo,
@@ -70,6 +73,12 @@ func TestWriteLock(t *testing.T) {
 	}
 
 	if string(b) != lg {
-		t.Errorf("Valid lock did not marshal to JSON as expected:\n\t(GOT): %s\n\t(WNT): %s", string(b), lg)
+		if *test.UpdateGolden {
+			if err = h.WriteTestFile(golden, string(b)); err != nil {
+				t.Fatal(err)
+			}
+		} else {
+			t.Errorf("Valid lock did not marshal to JSON as expected:\n\t(GOT): %s\n\t(WNT): %s", lg, string(b))
+		}
 	}
 }

manifest_test.go

@@ -63,7 +63,8 @@ func TestWriteManifest(t *testing.T) {
 	h := test.NewHelper(t)
 	defer h.Cleanup()
 
-	jg := h.GetTestFileString("manifest/golden.json")
+	golden := "manifest/golden.json"
+	jg := h.GetTestFileString(golden)
 	c, _ := gps.NewSemverConstraint("^v0.12.0")
 	m := &Manifest{
 		Dependencies: map[gps.ProjectRoot]gps.ProjectProperties{
@@ -89,6 +90,12 @@ func TestWriteManifest(t *testing.T) {
 	}
 
 	if string(b) != jg {
-		t.Errorf("Valid manifest did not marshal to JSON as expected:\n\t(GOT): %s\n\t(WNT): %s", string(b), jg)
+		if *test.UpdateGolden {
+			if err = h.WriteTestFile(golden, string(b)); err != nil {
+				t.Fatal(err)
+			}
+		} else {
+			t.Errorf("Valid manifest did not marshal to JSON as expected:\n\t(GOT): %s\n\t(WNT): %s", jg, string(b))
+		}
 	}
 }

project_test.go

@@ -20,7 +20,7 @@ func TestFindRoot(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	want := filepath.Join(wd, "_testdata", "rootfind")
+	want := filepath.Join(wd, "testdata", "rootfind")
 	got1, err := findProjectRoot(want)
 	if err != nil {
 		t.Errorf("Unexpected error while finding root: %s", err)

test/test.go

@@ -6,6 +6,7 @@ package test
 
 import (
 	"bytes"
+	"flag"
 	"fmt"
 	"go/format"
 	"io"
@@ -21,8 +22,9 @@ import (
 )
 
 var (
-	ExeSuffix string // ".exe" on Windows
-	mu        sync.Mutex
+	ExeSuffix    string // ".exe" on Windows
+	mu           sync.Mutex
+	UpdateGolden = flag.Bool("update", false, "update .golden files")
 )
 
 func init() {
@@ -420,10 +422,17 @@ func (h *Helper) TempFile(path, contents string) {
 	h.Must(ioutil.WriteFile(filepath.Join(h.tempdir, path), bytes, 0644))
 }
 
+// WriteTestFile writes a file to the testdata directory from memory.  src is
+// relative to ./testdata.
+func (h *Helper) WriteTestFile(src string, content string) error {
+	err := ioutil.WriteFile(filepath.Join(h.origWd, "testdata", src), []byte(content), 0666)
+	return err
+}
+
 // GetTestFile reads a file from the testdata directory into memory.  src is
-// relative to ./_testdata.
+// relative to ./testdata.
 func (h *Helper) GetTestFile(src string) io.ReadCloser {
-	content, err := os.Open(filepath.Join(h.origWd, "_testdata", src))
+	content, err := os.Open(filepath.Join(h.origWd, "testdata", src))
 	if err != nil {
 		panic(err)
 	}
@@ -431,7 +440,7 @@ func (h *Helper) GetTestFile(src string) io.ReadCloser {
 }
 
 // GetTestFileString reads a file from the testdata directory into memory.  src is
-// relative to ./_testdata.
+// relative to ./testdata.
 func (h *Helper) GetTestFileString(src string) string {
 	content, err := ioutil.ReadAll(h.GetTestFile(src))
 	if err != nil {
@@ -442,7 +451,7 @@ func (h *Helper) GetTestFileString(src string) string {
 
 // TempCopy copies a temporary file from testdata into the temporary directory.
 // dest is relative to the temp directory location, and src is relative to
-// ./_testdata.
+// ./testdata.
 func (h *Helper) TempCopy(dest, src string) {
 	in := h.GetTestFile(src)
 	defer in.Close()

txn_writer_test.go

@@ -94,12 +94,14 @@ func TestTxnWriter(t *testing.T) {
 	reset()
 
 	// super basic manifest and lock
-	expectedManifest := h.GetTestFileString("txn_writer/expected_manifest.json")
-	expectedLock := h.GetTestFileString("txn_writer/expected_lock.json")
+	goldenMan := "txn_writer/expected_manifest.json"
+	goldenLock := "txn_writer/expected_lock.json"
+	expectedManifest := h.GetTestFileString(goldenMan)
+	expectedLock := h.GetTestFileString(goldenLock)
 
-	m, err := readManifest(h.GetTestFile("txn_writer/expected_manifest.json"))
+	m, err := readManifest(h.GetTestFile(goldenMan))
 	h.Must(err)
-	l, err := readLock(h.GetTestFile("txn_writer/expected_lock.json"))
+	l, err := readLock(h.GetTestFile(goldenLock))
 	h.Must(err)
 
 	// Just write manifest
@@ -111,7 +113,14 @@ func TestTxnWriter(t *testing.T) {
 
 	diskm := h.ReadManifest()
 	if expectedManifest != diskm {
-		t.Fatalf("expected %s, got %s", expectedManifest, diskm)
+		if *test.UpdateGolden {
+			expectedManifest = diskm
+			if err = h.WriteTestFile(goldenMan, diskm); err != nil {
+				t.Fatal(err)
+			}
+		} else {
+			t.Fatalf("expected %s, got %s", expectedManifest, diskm)
+		}
 	}
 
 	// Manifest and lock, but no vendor
@@ -128,7 +137,14 @@ func TestTxnWriter(t *testing.T) {
 
 	diskl := h.ReadLock()
 	if expectedLock != diskl {
-		t.Fatalf("expected %s, got %s", expectedLock, diskl)
+		if *test.UpdateGolden {
+			expectedLock = diskl
+			if err = h.WriteTestFile(goldenLock, diskl); err != nil {
+				t.Fatal(err)
+			}
+		} else {
+			t.Fatalf("expected %s, got %s", expectedLock, diskl)
+		}
 	}
 
 	h.Must(sw.WriteAllSafe(true))