Don't dirty work tree when running tests

Because we run our golang integration tests "in tree" (due to
the need to be under $GOPATH and have a vendor folder around), the
"command-output" folder was getting left behind, dirtying the worktree
after building.

This change does two things:

1. On a succecssful run, remove the folder.
2. Ignore the folder via .gitignore (this way if a test fails and you
do `git add .` you don't end up commiting this folder).

.gitignore

@@ -3,7 +3,7 @@
 **/.vscode/
 coverage.cov
 *.coverprofile
-custom_node/
 
-# Too much awesome to store in Git.
-.pulumi
+# Go tests run "in tree" and this folder will linger if they fail (the integration test framework cleans
+# it up when they pass.)
+**/command-output/

pkg/testing/integration/program.go

@@ -474,8 +474,8 @@ func (pt *programTester) testLifeCycleInitAndDestroy() error {
 	}
 
 	testFinished := false
-	if tmpdir != "" {
-		defer func() {
+	defer func() {
+		if tmpdir != "" {
 			if !testFinished || pt.t.Failed() {
 				// Test aborted or failed. Maybe copy to "failed tests" directory.
 				failedTestsDir := os.Getenv("PULUMI_FAILED_TESTS_DIR")
@@ -486,8 +486,15 @@ func (pt *programTester) testLifeCycleInitAndDestroy() error {
 			} else {
 				contract.IgnoreError(os.RemoveAll(tmpdir))
 			}
-		}()
-	}
+		} else {
+			// When tmpdir is empty, we ran "in tree", which means we wrote output
+			// to the "command-output" folder in the projdir, and we should clean
+			// it up if the test passed
+			if testFinished && !pt.t.Failed() {
+				contract.IgnoreError(os.RemoveAll(filepath.Join(projdir, commandOutputFolderName)))
+			}
+		}
+	}()
 
 	err = pt.testLifeCycleInitialize(projdir)
 	if err != nil {

pkg/testing/integration/program_test.go

@@ -58,7 +58,7 @@ func TestRunCommandLog(t *testing.T) {
 	err = RunCommand(nil, "node", args, tempdir, opts)
 	assert.Nil(t, err)
 
-	matches, err := filepath.Glob(filepath.Join(tempdir, "command-output", "node.*"))
+	matches, err := filepath.Glob(filepath.Join(tempdir, commandOutputFolderName, "node.*"))
 	assert.Nil(t, err)
 	assert.Equal(t, 1, len(matches))
 

pkg/testing/integration/util.go

@@ -64,8 +64,12 @@ func uniqueSuffix() string {
 	return suffix
 }
 
+const (
+	commandOutputFolderName = "command-output"
+)
+
 func writeCommandOutput(commandName, runDir string, output []byte) (string, error) {
-	logFileDir := filepath.Join(runDir, "command-output")
+	logFileDir := filepath.Join(runDir, commandOutputFolderName)
 	if err := os.MkdirAll(logFileDir, 0700); err != nil {
 		return "", errors.Wrapf(err, "Failed to create '%s'", logFileDir)
 	}