[BUGFIX beta] Make sure the component-class blueprint generates a signature in a TS project

blueprints/-utils.js

@@ -1,9 +1,33 @@
 const { dasherize } = require('ember-cli-string-utils');
+const { EOL } = require('os');
+
+function generateComponentSignature(componentName) {
+  let args = `  // The arguments accepted by the component${EOL}  Args: {};`;
+
+  let blocks =
+    `  // Any blocks yielded by the component${EOL}` +
+    `  Blocks: {${EOL}` +
+    `    default: []${EOL}` +
+    `  };`;
+
+  let element =
+    `  // The element to which \`...attributes\` is applied in the component template${EOL}` +
+    `  Element: null;`;
+
+  return (
+    `export interface ${componentName}Signature {${EOL}` +
+    `${args}${EOL}` +
+    `${blocks}${EOL}` +
+    `${element}${EOL}` +
+    `}${EOL}`
+  );
+}
 
 function modulePrefixForProject(project) {
   return dasherize(project.config().modulePrefix);
 }
 
 module.exports = {
+  generateComponentSignature,
   modulePrefixForProject,
 };

blueprints/component-class/files/__root__/__path__/__name__.ts

@@ -1,3 +1,4 @@
 <%= importComponent %>
 <%= importTemplate %>
+<%= componentSignature %>
 export default <%= defaultExport %>

blueprints/component-class/index.js

@@ -8,6 +8,7 @@ const getPathOption = require('ember-cli-get-component-path-option');
 const normalizeEntityName = require('ember-cli-normalize-entity-name');
 const { EOL } = require('os');
 const { has } = require('@ember/edition-utils');
+const { generateComponentSignature } = require('../-utils');
 
 const maybePolyfillTypeScriptBlueprints = require('../-maybe-polyfill-typescript-blueprints');
 
@@ -49,9 +50,17 @@ module.exports = {
     },
   ],
 
+  /**
+    Flag to let us correctly handle the case where we are running against a
+    version of Ember CLI which does not support TS-based emit, and where we
+    therefore *must* not emit a `defaultExport` local which includes a type
+    parameter in the exported function call or class definition.
+   */
+  _isUsingTS: false,
+
   init() {
     this._super && this._super.init.apply(this, arguments);
-    maybePolyfillTypeScriptBlueprints(this);
+    this._isUsingTS = maybePolyfillTypeScriptBlueprints(this);
     let isOctane = has('octane');
 
     this.availableOptions.forEach((option) => {
@@ -134,6 +143,7 @@ module.exports = {
     let importComponent = '';
     let importTemplate = '';
     let defaultExport = '';
+    let componentSignature = '';
 
     // if we're in an addon, build import statement
     if (options.project.isEmberCLIAddon() || (options.inRepoAddon && !options.inDummy)) {
@@ -161,17 +171,28 @@ module.exports = {
         break;
       case '@glimmer/component':
         importComponent = `import Component from '@glimmer/component';`;
-        defaultExport = `class ${classifiedModuleName}Component extends Component {}`;
+        if (this._isUsingTS) {
+          componentSignature = generateComponentSignature(classifiedModuleName);
+          defaultExport = `class ${classifiedModuleName}Component extends Component<${classifiedModuleName}Signature> {}`;
+        } else {
+          defaultExport = `class ${classifiedModuleName}Component extends Component {}`;
+        }
         break;
       case '@ember/component/template-only':
         importComponent = `import templateOnly from '@ember/component/template-only';`;
-        defaultExport = `templateOnly();`;
+        if (this._isUsingTS) {
+          componentSignature = generateComponentSignature(classifiedModuleName);
+          defaultExport = `templateOnly<${classifiedModuleName}Signature>();`;
+        } else {
+          defaultExport = `templateOnly();`;
+        }
         break;
     }
 
     return {
       importTemplate,
       importComponent,
+      componentSignature,
       defaultExport,
       path: getPathOption(options),
       componentClass,

blueprints/component/index.js

@@ -9,6 +9,7 @@ const getPathOption = require('ember-cli-get-component-path-option');
 const normalizeEntityName = require('ember-cli-normalize-entity-name');
 const { EOL } = require('os');
 const { has } = require('@ember/edition-utils');
+const { generateComponentSignature } = require('../-utils');
 
 const maybePolyfillTypeScriptBlueprints = require('../-maybe-polyfill-typescript-blueprints');
 
@@ -273,7 +274,7 @@ module.exports = {
       case '@glimmer/component':
         importComponent = `import Component from '@glimmer/component';`;
         if (this._isUsingTS) {
-          componentSignature = signatureFor(classifiedModuleName);
+          componentSignature = generateComponentSignature(classifiedModuleName);
           defaultExport = `class ${classifiedModuleName}Component extends Component<${classifiedModuleName}Signature> {}`;
         } else {
           defaultExport = `class ${classifiedModuleName}Component extends Component {}`;
@@ -282,7 +283,7 @@ module.exports = {
       case '@ember/component/template-only':
         importComponent = `import templateOnly from '@ember/component/template-only';`;
         if (this._isUsingTS) {
-          componentSignature = signatureFor(classifiedModuleName);
+          componentSignature = generateComponentSignature(classifiedModuleName);
           defaultExport = `templateOnly<${classifiedModuleName}Signature>();`;
         } else {
           defaultExport = `templateOnly();`;
@@ -300,25 +301,3 @@ module.exports = {
     };
   },
 };
-
-function signatureFor(classifiedModuleName) {
-  let args = `  // The arguments accepted by the component${EOL}  Args: {};`;
-
-  let blocks =
-    `  // Any blocks yielded by the component${EOL}` +
-    `  Blocks: {${EOL}` +
-    `    default: []${EOL}` +
-    `  };`;
-
-  let element =
-    `  // The element to which \`...attributes\` is applied in the component template${EOL}` +
-    `  Element: null;`;
-
-  return (
-    `interface ${classifiedModuleName}Signature {${EOL}` +
-    `${args}${EOL}` +
-    `${blocks}${EOL}` +
-    `${element}${EOL}` +
-    `}${EOL}`
-  );
-}