fix(esbuild): fix static properties transpile when useDefineForClassFields false

packages/vite/src/node/__tests__/plugins/esbuild.spec.ts

@@ -383,6 +383,21 @@ describe('transformWithEsbuild', () => {
       const actual = await transformClassCode('es2022', {})
       expect(actual).toBe(defineForClassFieldsFalseTransformedCode)
     })
+
+    test('useDefineForClassFields: false and static property should not be transpile to static block', async () => {
+      const result = await transformWithEsbuild(
+        `
+          class foo {
+            static bar = 'bar'
+          }
+        `,
+        'bar.ts',
+        {
+          target: 'esnext',
+        },
+      )
+      expect(result?.code).not.toContain('static {')
+    })
   })
 })
 

packages/vite/src/node/plugins/esbuild.ts

@@ -96,6 +96,7 @@ export async function transformWithEsbuild(
   }
 
   let tsconfigRaw = options?.tsconfigRaw
+  const fallbackSupported: Record<string, boolean> = {}
 
   // if options provide tsconfigRaw in string, it takes highest precedence
   if (typeof tsconfigRaw !== 'string') {
@@ -150,6 +151,15 @@ export async function transformWithEsbuild(
       compilerOptions.experimentalDecorators = true
     }
 
+    // Compat with esbuild 0.17 where static properties are transpiled to
+    // static blocks when `useDefineForClassFields` is false. Its support
+    // is not great yet, so temporarily disable it for now.
+    // TODO: Remove this in Vite 5, don't pass hardcoded `esnext` target
+    // to `transformWithEsbuild` in the esbuild plugin.
+    if (compilerOptions.useDefineForClassFields !== true) {
+      fallbackSupported['class-static-blocks'] = false
+    }
+
     // esbuild uses tsconfig fields when both the normal options and tsconfig was set
     // but we want to prioritize the normal options
     if (options) {
@@ -172,6 +182,10 @@ export async function transformWithEsbuild(
     ...options,
     loader,
     tsconfigRaw,
+    supported: {
+      ...fallbackSupported,
+      ...options?.supported,
+    },
   }
 
   // Some projects in the ecosystem are calling this function with an ESBuildOptions