feat: babel plugin: generate our own expect

jestjs · Dec 5, 2020 · 1f16421 · 1f16421
1 parent 009ca12
commit 1f16421
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Showing 2 changed files with 41 additions and 12 deletions.
diff --git a/...ages/babel-plugin-jest-deadlines/src/__tests__/__snapshots__/deadlinesPlugin.test.ts.snap b/...ages/babel-plugin-jest-deadlines/src/__tests__/__snapshots__/deadlinesPlugin.test.ts.snap
@@ -8,8 +8,10 @@ async function foo() {
 
       ↓ ↓ ↓ ↓ ↓ ↓
 
+const _expect = require("@jest/globals").expect;
+
 async function foo() {
-  await expect.withinDeadline(bar());
+  await _expect.withinDeadline(bar());
 }
 
 
@@ -23,8 +25,10 @@ async function foo() {
 
       ↓ ↓ ↓ ↓ ↓ ↓
 
+const _expect = require("@jest/globals").expect;
+
 async function foo() {
-  await expect.withinDeadline(bar());
+  await _expect.withinDeadline(expect.withinDeadline(bar()));
 }
 
 
@@ -38,8 +42,10 @@ async function foo() {
 
       ↓ ↓ ↓ ↓ ↓ ↓
 
+const _expect = require("@jest/globals").expect;
+
 async function foo() {
-  await expect.withinDeadline(expect(bar()).resolves.toBe("hot potatoes"));
+  await _expect.withinDeadline(expect(bar()).resolves.toBe("hot potatoes"));
 }
 
 
@@ -53,8 +59,10 @@ async function foo() {
 
       ↓ ↓ ↓ ↓ ↓ ↓
 
+const _expect = require("@jest/globals").expect;
+
 async function foo() {
-  return await expect.withinDeadline(bar());
+  return await _expect.withinDeadline(bar());
 }
 
 
@@ -68,8 +76,10 @@ async function foo() {
 
       ↓ ↓ ↓ ↓ ↓ ↓
 
+const _expect = require("@jest/globals").expect;
+
 async function foo() {
-  await expect.withinDeadline(bar(1, await expect.withinDeadline(quux()), 3));
+  await _expect.withinDeadline(bar(1, await _expect.withinDeadline(quux()), 3));
 }
 
 
@@ -84,9 +94,11 @@ async function foo() {
 
       ↓ ↓ ↓ ↓ ↓ ↓
 
+const _expect = require("@jest/globals").expect;
+
 async function foo() {
-  await expect.withinDeadline(bar(1, 2, 3));
-  await expect.withinDeadline(quux(1, 2, 3));
+  await _expect.withinDeadline(bar(1, 2, 3));
+  await _expect.withinDeadline(quux(1, 2, 3));
 }
 
 

diff --git a/packages/babel-plugin-jest-deadlines/src/index.ts b/packages/babel-plugin-jest-deadlines/src/index.ts
@@ -7,13 +7,33 @@
  */
 
 import type {PluginObj, types as babelTypes} from '@babel/core';
+import type {Identifier} from '@babel/types';
 
 export default ({
   types: t,
 }: {
   types: typeof babelTypes;
 }): PluginObj<{
+  ourExpect: Identifier;
 }> => ({
+  pre({path: program}) {
+    this.ourExpect = program.scope.generateUidIdentifier('expect');
+
+    // const _expect = require("@jest/globals").expect;
+    const decl = t.variableDeclaration('const', [
+      t.variableDeclarator(
+        this.ourExpect,
+        t.memberExpression(
+          t.callExpression(t.identifier('require'), [
+            t.stringLiteral('@jest/globals'),
+          ]),
+          t.identifier('expect'),
+        ),
+      ),
+    ]);
+
+    program.unshiftContainer('body', decl);
+  },
   visitor: {
     AwaitExpression(path) {
       const original = path.node.argument;
@@ -25,7 +45,7 @@ export default ({
       if (t.isMemberExpression(original.callee)) {
         const member = original.callee;
         if (
-          t.isIdentifier(member.object, {name: 'expect'}) &&
+          t.isIdentifier(member.object, this.ourExpect) &&
           t.isIdentifier(member.property, {name: 'withinDeadline'})
         ) {
           return;
@@ -35,10 +55,7 @@ export default ({
       path.replaceWith(
         t.awaitExpression(
           t.callExpression(
-            t.memberExpression(
-              t.identifier('expect'),
-              t.identifier('withinDeadline'),
-            ),
+            t.memberExpression(this.ourExpect, t.identifier('withinDeadline')),
             [path.node.argument],
           ),
         ),