Log warnings to stderr for "bundle validate -o json" (#2109)

## Changes
Previously diagnostics were not seen in JSON output mode. This change
prints them to stderr.

This also fixes acceptance tests to preprocess all output with
s/execPath/$CLI/ not just output.txt.

## Tests
Existing acceptance tests. In one case I've added non-json command to
check that they match in output.

acceptance/acceptance_test.go

@@ -55,12 +55,15 @@ func TestAccept(t *testing.T) {
 	// Do not read user's ~/.databrickscfg
 	t.Setenv(env.HomeEnvVar(), homeDir)
 
+	repls := testdiff.ReplacementsContext{}
+	repls.Set(execPath, "$CLI")
+
 	testDirs := getTests(t)
 	require.NotEmpty(t, testDirs)
 	for _, dir := range testDirs {
 		t.Run(dir, func(t *testing.T) {
 			t.Parallel()
-			runTest(t, dir)
+			runTest(t, dir, repls)
 		})
 	}
 }
@@ -85,7 +88,7 @@ func getTests(t *testing.T) []string {
 	return testDirs
 }
 
-func runTest(t *testing.T, dir string) {
+func runTest(t *testing.T, dir string, repls testdiff.ReplacementsContext) {
 	var tmpDir string
 	var err error
 	if KeepTmp {
@@ -112,7 +115,7 @@ func runTest(t *testing.T, dir string) {
 	outB, err := cmd.CombinedOutput()
 
 	out := formatOutput(string(outB), err)
-	out = strings.ReplaceAll(out, os.Getenv("CLI"), "$CLI")
+	out = repls.Replace(out)
 	doComparison(t, filepath.Join(dir, "output.txt"), "script output", out)
 
 	for key := range outputs {
@@ -131,7 +134,8 @@ func runTest(t *testing.T, dir string) {
 			continue
 		}
 		pathExpected := filepath.Join(dir, key)
-		doComparison(t, pathExpected, pathNew, string(newValBytes))
+		newVal := repls.Replace(string(newValBytes))
+		doComparison(t, pathExpected, pathNew, newVal)
 	}
 
 	// Make sure there are not unaccounted for new files
@@ -152,6 +156,7 @@ func runTest(t *testing.T, dir string) {
 			// Show the contents & support overwrite mode for it:
 			pathNew := filepath.Join(tmpDir, name)
 			newVal := testutil.ReadFile(t, pathNew)
+			newVal = repls.Replace(newVal)
 			doComparison(t, filepath.Join(dir, name), filepath.Join(tmpDir, name), newVal)
 		}
 	}

acceptance/bundle/override/job_tasks/out.development.stderr.txt

@@ -0,0 +1,6 @@
+
+>>> errcode $CLI bundle validate -o json -t development
+Error: file ./test1.py not found
+
+
+Exit code: 1

acceptance/bundle/override/job_tasks/output.txt

@@ -1,8 +1,3 @@
-
->>> errcode $CLI bundle validate -o json -t development
-Error: file ./test1.py not found
-
-Exit code: 1
 {
   "name": "job",
   "queue": {
@@ -36,6 +31,7 @@ Exit code: 1
 >>> errcode $CLI bundle validate -o json -t staging
 Error: file ./test1.py not found
 
+
 Exit code: 1
 {
   "name": "job",
@@ -66,3 +62,16 @@ Exit code: 1
     }
   ]
 }
+
+>>> errcode $CLI bundle validate -t staging
+Error: file ./test1.py not found
+
+Name: override_job_tasks
+Target: staging
+Workspace:
+  User: tester@databricks.com
+  Path: /Workspace/Users/tester@databricks.com/.bundle/override_job_tasks/staging
+
+Found 1 error
+
+Exit code: 1

acceptance/bundle/override/job_tasks/script

@@ -1,2 +1,3 @@
-trace errcode $CLI bundle validate -o json -t development | jq .resources.jobs.foo
+trace errcode $CLI bundle validate -o json -t development 2> out.development.stderr.txt | jq .resources.jobs.foo
 trace errcode $CLI bundle validate -o json -t staging | jq .resources.jobs.foo
+trace errcode $CLI bundle validate -t staging

acceptance/bundle/override/merge-string-map/output.txt

@@ -1,5 +1,9 @@
 
 >>> $CLI bundle validate -o json -t dev
+Warning: expected map, found string
+  at resources.clusters.my_cluster
+  in databricks.yml:6:17
+
 {
   "clusters": {
     "my_cluster": {

cmd/bundle/validate.go

@@ -11,18 +11,17 @@ import (
 	"github.com/databricks/cli/bundle/render"
 	"github.com/databricks/cli/cmd/bundle/utils"
 	"github.com/databricks/cli/cmd/root"
-	"github.com/databricks/cli/libs/diag"
 	"github.com/databricks/cli/libs/flags"
 	"github.com/spf13/cobra"
 )
 
-func renderJsonOutput(cmd *cobra.Command, b *bundle.Bundle, diags diag.Diagnostics) error {
+func renderJsonOutput(cmd *cobra.Command, b *bundle.Bundle) error {
 	buf, err := json.MarshalIndent(b.Config.Value().AsAny(), "", "  ")
 	if err != nil {
 		return err
 	}
 	_, _ = cmd.OutOrStdout().Write(buf)
-	return diags.Error()
+	return nil
 }
 
 func newValidateCommand() *cobra.Command {
@@ -66,7 +65,23 @@ func newValidateCommand() *cobra.Command {
 
 			return nil
 		case flags.OutputJSON:
-			return renderJsonOutput(cmd, b, diags)
+			renderOpts := render.RenderOptions{RenderSummaryTable: false}
+			err1 := render.RenderDiagnostics(cmd.ErrOrStderr(), b, diags, renderOpts)
+			err2 := renderJsonOutput(cmd, b)
+
+			if err2 != nil {
+				return err2
+			}
+
+			if err1 != nil {
+				return err1
+			}
+
+			if diags.HasError() {
+				return root.ErrAlreadyPrinted
+			}
+
+			return nil
 		default:
 			return fmt.Errorf("unknown output type %s", root.OutputType(cmd))
 		}