feat(ssr): add LWC version comment to compiled components (#5186)

salesforce · Feb 4, 2025 · 3056753 · 3056753
1 parent 4cab9e6
commit 3056753
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Showing 2 changed files with 31 additions and 2 deletions.
diff --git a/packages/@lwc/ssr-compiler/src/__tests__/compilation.spec.ts b/packages/@lwc/ssr-compiler/src/__tests__/compilation.spec.ts
@@ -1,6 +1,7 @@
 import path from 'node:path';
 import { describe, test, expect } from 'vitest';
 import { CompilerError } from '@lwc/errors';
+import { LWC_VERSION_COMMENT_REGEX } from '@lwc/shared';
 import { compileComponentForSSR } from '../index';
 
 expect.addSnapshotSerializer({
@@ -42,6 +43,15 @@ describe('component compilation', () => {
         const { code } = compileComponentForSSR(src, filename, {});
         expect(code).toContain('import explicit from "./explicit.html"');
     });
+    test('components include LWC version comment', () => {
+        const src = `
+      import { LightningElement } from 'lwc';
+      export default class extends LightningElement {}
+      `;
+        const filename = path.resolve('component.js');
+        const { code } = compileComponentForSSR(src, filename, {});
+        expect(code).toMatch(LWC_VERSION_COMMENT_REGEX);
+    });
     test('supports .ts file imports', () => {
         const src = `
             import { LightningElement } from 'lwc';

diff --git a/packages/@lwc/ssr-compiler/src/compile-js/index.ts b/packages/@lwc/ssr-compiler/src/compile-js/index.ts
@@ -10,6 +10,7 @@ import { traverse, builders as b, is } from 'estree-toolkit';
 import { parseModule } from 'meriyah';
 
 import { DecoratorErrors } from '@lwc/errors';
+import { LWC_VERSION_COMMENT, type CompilationMode } from '@lwc/shared';
 import { transmogrify } from '../transmogrify';
 import { ImportManager } from '../imports';
 import { replaceLwcImport, replaceNamedLwcExport, replaceAllLwcExport } from './lwc-import';
@@ -25,9 +26,9 @@ import type {
     Identifier as EsIdentifier,
     Program as EsProgram,
     Decorator as EsDecorator,
+    Comment as EsComment,
 } from 'estree';
 import type { Visitors, ComponentMetaState } from './types';
-import type { CompilationMode } from '@lwc/shared';
 
 const visitors: Visitors = {
     $: { scope: true },
@@ -89,6 +90,20 @@ const visitors: Visitors = {
                 node.id = b.identifier('DefaultComponentName');
                 state.lwcClassName = 'DefaultComponentName';
             }
+
+            // There's no builder for comment nodes :\
+            const lwcVersionComment: EsComment = {
+                type: 'Block',
+                value: LWC_VERSION_COMMENT,
+            };
+
+            // Add LWC version comment to end of class body
+            const { body } = node;
+            if (body.trailingComments) {
+                body.trailingComments.push(lwcVersionComment);
+            } else {
+                body.trailingComments = [lwcVersionComment];
+            }
         }
     },
     PropertyDefinition(path, state) {
@@ -324,6 +339,10 @@ export default function compileJS(
     }
 
     return {
-        code: generate(ast, {}),
+        code: generate(ast, {
+            // The AST generated by meriyah doesn't seem to include comments,
+            // so this just preserves the LWC version comment we added
+            comments: true,
+        }),
     };
 }