fix(fake-js): patch void 0 to undefined

sxzz · sxzz · commit 04663d61eb3f · 2026-01-24T08:25:17.000+08:00
closes #171
diff --git a/src/fake-js.ts b/src/fake-js.ts
@@ -429,10 +429,23 @@ export function createFakeJsPlugin({
         const transformedDeps = (depsFn.body as t.ArrayExpression)
           .elements as t.Expression[]
         for (const [i, originalDep] of declaration.deps.entries()) {
+          let transformedDep = transformedDeps[i]
+          if (
+            transformedDep.type === 'UnaryExpression' &&
+            transformedDep.operator === 'void'
+          ) {
+            transformedDep = {
+              ...t.identifier('undefined'),
+              loc: transformedDep.loc,
+              start: transformedDep.start,
+              end: transformedDep.end,
+            }
+          }
+
           if (originalDep.replace) {
-            originalDep.replace(transformedDeps[i])
+            originalDep.replace(transformedDep)
           } else {
-            Object.assign(originalDep, transformedDeps[i])
+            Object.assign(originalDep, transformedDep)
           }
         }
 
diff --git a/tests/rollup-plugin-dts/typeof-undefined-alias/index.d.ts b/tests/rollup-plugin-dts/typeof-undefined-alias/index.d.ts
@@ -0,0 +1,2 @@
+export let undefined: string
+export type T = typeof undefined
diff --git a/tests/rollup-plugin-dts/typeof-undefined-alias/known-diff.patch b/tests/rollup-plugin-dts/typeof-undefined-alias/known-diff.patch
@@ -0,0 +1,11 @@
+Index: diff.patch
+===================================================================
+--- diff.patch
++++ diff.patch
+@@ -1,5 +1,4 @@
+ // index.d.ts
+ declare let undefined$1: string
+ type T = typeof undefined$1
+-export { undefined$1 as undefined }
+-export { T }
++export { T, undefined$1 as undefined }
diff --git a/tests/rollup-plugin-dts/typeof-undefined-alias/snapshot.d.ts b/tests/rollup-plugin-dts/typeof-undefined-alias/snapshot.d.ts
@@ -0,0 +1,6 @@
+// index.d.ts
+//#region tests/rollup-plugin-dts/typeof-undefined-alias/index.d.ts
+declare let undefined$1: string;
+type T = typeof undefined$1;
+//#endregion
+export { T, undefined$1 as undefined };
diff --git a/tests/rollup-plugin-dts/typeof-undefined/index.d.ts b/tests/rollup-plugin-dts/typeof-undefined/index.d.ts
@@ -0,0 +1 @@
+export type T = typeof undefined | typeof NaN
diff --git a/tests/rollup-plugin-dts/typeof-undefined/snapshot.d.ts b/tests/rollup-plugin-dts/typeof-undefined/snapshot.d.ts
@@ -0,0 +1,5 @@
+// index.d.ts
+//#region tests/rollup-plugin-dts/typeof-undefined/index.d.ts
+type T = typeof undefined | typeof NaN;
+//#endregion
+export { T };

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	`+export let undefined: string`
	`2`	`+export type T = typeof undefined`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+export type T = typeof undefined \| typeof NaN`