Return more complex diff response to magician

This is a prerequisite to hashicorp/terraform-provider-google#21287 because it will allow distinguishing between added, modified, and removed resources.

I also made the computation of the primary schema diff happen at build time, since it is a static value.

.ci/magician/cmd/generate_comment.go

@@ -73,6 +73,10 @@ type diffCommentData struct {
 	Errors          []Errors
 }
 
+type simpleSchemaDiff struct {
+	AddedResources, ModifiedResources, RemovedResources []string
+}
+
 const allowBreakingChangesLabel = "override-breaking-change"
 
 var gcEnvironmentVariables = [...]string{
@@ -303,7 +307,7 @@ func execGenerateComment(prNumber int, ghTokenMagicModules, buildId, buildStep,
 			data.MissingTests = missingTests
 		}
 
-		affectedResources, err := changedSchemaResources(diffProcessorPath, rnr)
+		affectedResources, err := computeAffectedResources(diffProcessorPath, rnr, repo)
 		if err != nil {
 			fmt.Println("computing changed resource schemas: ", err)
 			errors[repo.Title] = append(errors[repo.Title], "The diff processor crashed while computing changed resource schemas.")
@@ -460,27 +464,31 @@ func computeBreakingChanges(diffProcessorPath string, rnr ExecRunner) ([]Breakin
 	return changes, rnr.PopDir()
 }
 
-func changedSchemaResources(diffProcessorPath string, rnr ExecRunner) ([]string, error) {
+func computeAffectedResources(diffProcessorPath string, rnr ExecRunner, repo source.Repo) ([]string, error) {
 	if err := rnr.PushDir(diffProcessorPath); err != nil {
 		return nil, err
 	}
 
-	output, err := rnr.Run("bin/diff-processor", []string{"changed-schema-resources"}, nil)
+	output, err := rnr.Run("bin/diff-processor", []string{"schema-diff"}, nil)
 	if err != nil {
 		return nil, err
 	}
 
-	fmt.Println("Resources with changed schemas: " + output)
+	fmt.Printf("Schema diff for %q: %s\n", repo.Name, output)
 
-	var labels []string
-	if err = json.Unmarshal([]byte(output), &labels); err != nil {
+	var simpleDiff simpleSchemaDiff
+	if err = json.Unmarshal([]byte(output), &simpleDiff); err != nil {
 		return nil, err
 	}
 
 	if err = rnr.PopDir(); err != nil {
 		return nil, err
 	}
-	return labels, nil
+	var resources []string
+	resources = append(resources, simpleDiff.AddedResources...)
+	resources = append(resources, simpleDiff.ModifiedResources...)
+	resources = append(resources, simpleDiff.RemovedResources...)
+	return resources, nil
 }
 
 // Run the missing test detector and return the results.

.ci/magician/cmd/generate_comment_test.go

@@ -89,11 +89,11 @@ func TestExecGenerateComment(t *testing.T) {
 			{"/mock/dir/tfoics", "git", []string{"diff", "origin/auto-pr-123456-old", "origin/auto-pr-123456", "--shortstat"}, map[string]string(nil)},
 			{"/mock/dir/magic-modules/tools/diff-processor", "make", []string{"build"}, diffProcessorEnv},
 			{"/mock/dir/magic-modules/tools/diff-processor", "bin/diff-processor", []string{"breaking-changes"}, map[string]string(nil)},
-			{"/mock/dir/magic-modules/tools/diff-processor", "bin/diff-processor", []string{"changed-schema-resources"}, map[string]string(nil)},
+			{"/mock/dir/magic-modules/tools/diff-processor", "bin/diff-processor", []string{"schema-diff"}, map[string]string(nil)},
 			{"/mock/dir/magic-modules/tools/diff-processor", "make", []string{"build"}, diffProcessorEnv},
 			{"/mock/dir/magic-modules/tools/diff-processor", "bin/diff-processor", []string{"breaking-changes"}, map[string]string(nil)},
 			{"/mock/dir/magic-modules/tools/diff-processor", "bin/diff-processor", []string{"detect-missing-tests", "/mock/dir/tpgb/google-beta/services"}, map[string]string(nil)},
-			{"/mock/dir/magic-modules/tools/diff-processor", "bin/diff-processor", []string{"changed-schema-resources"}, map[string]string(nil)},
+			{"/mock/dir/magic-modules/tools/diff-processor", "bin/diff-processor", []string{"schema-diff"}, map[string]string(nil)},
 		},
 	} {
 		if actualCalls, ok := mr.Calls(method); !ok {

.ci/magician/cmd/mock_runner_test.go

@@ -70,7 +70,7 @@ func NewMockRunner() MockRunner {
 			"/mock/dir/magic-modules/.ci/magician git [clone -b auto-pr-123456 https://modular-magician:*******@github.com/modular-magician/terraform-provider-google-beta /mock/dir/tpgb] map[]": "",
 			"/mock/dir/magic-modules/tools/diff-processor bin/diff-processor [breaking-changes] map[]":                                                                                            "",
 			"/mock/dir/magic-modules/tools/diff-processor make [build] " + sortedEnvString(diffProcessorEnv):                                                                                      "",
-			"/mock/dir/magic-modules/tools/diff-processor bin/diff-processor [changed-schema-resources] map[]":                                                                                    "[\"google_alloydb_instance\"]",
+			"/mock/dir/magic-modules/tools/diff-processor bin/diff-processor [schema-diff] map[]":                                                                                                 "{\"AddedResources\": [\"google_alloydb_instance\"]}",
 			"/mock/dir/magic-modules/tools/diff-processor bin/diff-processor [detect-missing-tests /mock/dir/tpgb/google-beta/services] map[]":                                                    `{"google_folder_access_approval_settings":{"SuggestedTest":"resource \"google_folder_access_approval_settings\" \"primary\" {\n  uncovered_field = # value needed\n}","Tests":["a","b","c"]}}`,
 			"/mock/dir/tgc git [diff origin/auto-pr-123456-old origin/auto-pr-123456 --shortstat] map[]":                                                                                          " 1 file changed, 10 insertions(+)\n",
 			"/mock/dir/tgc git [fetch origin auto-pr-123456-old] map[]":                                                                                                                           "",

tools/diff-processor/cmd/breaking_changes.go

@@ -27,7 +27,7 @@ func newBreakingChangesCmd(rootOptions *rootOptions) *cobra.Command {
 	o := &breakingChangesOptions{
 		rootOptions: rootOptions,
 		computeSchemaDiff: func() diff.SchemaDiff {
-			return diff.ComputeSchemaDiff(oldProvider.ResourceMap(), newProvider.ResourceMap())
+			return schemaDiff
 		},
 		stdout: os.Stdout,
 	}

tools/diff-processor/cmd/detect_missing_docs.go

@@ -37,7 +37,7 @@ func newDetectMissingDocsCmd(rootOptions *rootOptions) *cobra.Command {
 	o := &detectMissingDocsOptions{
 		rootOptions: rootOptions,
 		computeSchemaDiff: func() diff.SchemaDiff {
-			return diff.ComputeSchemaDiff(oldProvider.ResourceMap(), newProvider.ResourceMap())
+			return schemaDiff
 		},
 		stdout: os.Stdout,
 	}

tools/diff-processor/cmd/detect_missing_tests.go

@@ -45,8 +45,6 @@ func (o *detectMissingTestsOptions) run(args []string) error {
 		glog.Infof("error reading path: %s, err: %v", path, err)
 	}
 
-	schemaDiff := diff.ComputeSchemaDiff(oldProvider.ResourceMap(), newProvider.ResourceMap())
-
 	missingTests, err := detector.DetectMissingTests(schemaDiff, allTests)
 	if err != nil {
 		return fmt.Errorf("error detecting missing tests: %v", err)

tools/diff-processor/cmd/root.go

@@ -24,6 +24,7 @@ func newRootCmd() (*cobra.Command, *rootOptions, error) {
 	cmd.AddCommand(newBreakingChangesCmd(o))
 	cmd.AddCommand(newChangedSchemaResourcesCmd(o))
 	cmd.AddCommand(newDetectMissingTestsCmd(o))
+	cmd.AddCommand(newSchemaDiffCmd(o))
 	return cmd, o, nil
 }