Create Block: Allow using locally installed packages with templates

packages/create-block/CHANGELOG.md

@@ -9,6 +9,7 @@
 ### New Features
 
 - Add support for handling static assets with the `assetsPath` field in the external template configuration ([#28038](https://github.com/WordPress/gutenberg/pull/28038)).
+- Allow using locally installed packages with templates ([#28105](https://github.com/WordPress/gutenberg/pull/28105)).
 
 ### Internal
 

packages/create-block/lib/templates.js

@@ -29,6 +29,7 @@ const predefinedBlockTemplates = {
  editorStyle: 'file:./editor.css',
  style: 'file:./style.css',
  },
+ templatesPath: join( __dirname, 'templates', 'es5' ),
  },
  esnext: {
  defaultValues: {
@@ -43,6 +44,7 @@ const predefinedBlockTemplates = {
  '@wordpress/i18n',
  ],
  },
+ templatesPath: join( __dirname, 'templates', 'esnext' ),
  },
 };
 
@@ -94,16 +96,41 @@ const externalTemplateExists = async ( templateName ) => {
  return true;
 };
 
+const configToTemplate = async ( {
+ assetsPath,
+ defaultValues = {},
+ templatesPath,
+} ) => {
+ if ( ! isObject( defaultValues ) || ! templatesPath ) {
+ throw new CLIError( 'Template found but invalid definition provided.' );
+ }
+
+ return {
+ defaultValues,
+ outputAssets: assetsPath ? await getOutputAssets( assetsPath ) : {},
+ outputTemplates: await getOutputTemplates( templatesPath ),
+ };
+};
+
 const getBlockTemplate = async ( templateName ) => {
  if ( predefinedBlockTemplates[ templateName ] ) {
- return {
- ...predefinedBlockTemplates[ templateName ],
- outputTemplates: await getOutputTemplates(
- join( __dirname, 'templates', templateName )
- ),
- outputAssets: {},
- };
+ return await configToTemplate(
+ predefinedBlockTemplates[ templateName ]
+ );
  }
+
+ try {
+ return await configToTemplate( require( templateName ) );
+ } catch ( error ) {
+ if ( error instanceof CLIError ) {
+ throw error;
+ } else if ( error.code !== 'MODULE_NOT_FOUND' ) {
+ throw new CLIError(
+ `Invalid block template loaded. Error: ${ error.message }`
+ );
+ }
+ }
+
  if ( ! ( await externalTemplateExists( templateName ) ) ) {
  throw new CLIError(
  `Invalid block template type name: "${ templateName }". Allowed values: ` +
@@ -126,26 +153,19 @@ const getBlockTemplate = async ( templateName ) => {
  cwd: tempCwd,
  } );
 
- const {
- defaultValues = {},
- templatesPath,
- assetsPath,
- } = require( require.resolve( templateName, {
- paths: [ tempCwd ],
- } ) );
- if ( ! isObject( defaultValues ) || ! templatesPath ) {
- throw new Error();
- }
-
- return {
- defaultValues,
- outputTemplates: await getOutputTemplates( templatesPath ),
- outputAssets: assetsPath ? await getOutputAssets( assetsPath ) : {},
- };
- } catch ( error ) {
- throw new CLIError(
- `Invalid template definition provided in "${ templateName }" package.`
+ return await configToTemplate(
+ require( require.resolve( templateName, {
+ paths: [ tempCwd ],
+ } ) )
  );
+ } catch ( error ) {
+ if ( error instanceof CLIError ) {
+ throw error;
+ } else {
+ throw new CLIError(
+ `Invalid block template downloaded. Error: ${ error.message }`
+ );
+ }
  } finally {
  if ( tempCwd ) {
  rimraf( tempCwd );