fix(power-assert): make power assertions work when using autoImport

src/assertify-statement.ts

@@ -1,19 +1,22 @@
 import { NodePath } from '@babel/traverse';
 import * as BabelTypes from '@babel/types';
+import createEspowerVisitor from 'babel-plugin-espower/create';
 
 import { InternalConfig } from './config';
 import generateAssertIdentifier from './generate-assert-identifier';
 
-export default (t: typeof BabelTypes, config: InternalConfig) => (
-  statementPath: NodePath<BabelTypes.Statement>,
-) => {
-  const statement = statementPath.node;
+export default (
+  babel: { types: typeof BabelTypes },
+  state: any,
+  config: InternalConfig,
+) => (statementPath: NodePath<BabelTypes.Statement>) => {
+  const { types: t } = babel;
+  const { scope, node: statement } = statementPath;
+
   if (t.isExpressionStatement(statement)) {
     const origExpr = statement.expression;
 
-    const assertIdentifier = generateAssertIdentifier(t, config)(
-      statementPath.scope,
-    );
+    const assertIdentifier = generateAssertIdentifier(t, config)(scope);
     assertIdentifier.loc = {
       start: origExpr.loc.start,
       end: origExpr.loc.start,
@@ -22,6 +25,19 @@ export default (t: typeof BabelTypes, config: InternalConfig) => (
     const newExpr = t.callExpression(assertIdentifier, [origExpr]);
     newExpr.loc = origExpr.loc;
     statement.expression = newExpr;
+
+    // register added import with scope so it is found for the next assertion
+    // for some reason, this needs to happen after we have referenced the import
+    // with our call expression, otherwise the import will be removed
+    (scope as any).crawl();
+
+    if (config.powerAssert) {
+      // Now let espower generate nice power assertions for this assertion
+      createEspowerVisitor(babel, {
+        embedAst: true,
+        patterns: [`${assertIdentifier.name}(value)`],
+      }).visitor.Program(statementPath, state);
+    }
   } else {
     throw statementPath.buildCodeFrameError(
       `Expected an expression statement, but got a statement of type ${

src/generate-assert-identifier.ts

@@ -43,8 +43,7 @@ const addImport = (scope: Scope, t: typeof BabelTypes, source: string) => {
       t.stringLiteral(source),
     ),
   );
-  // recrawl scope so the added import is found for the next assertion
-  (scope as any).crawl();
+
   return id;
 };
 

src/index.ts

@@ -1,6 +1,5 @@
 import { PluginObj } from '@babel/core';
 import * as BabelTypes from '@babel/types';
-import createEspowerVisitor from 'babel-plugin-espower/create';
 import { NodePath } from 'babel-traverse';
 
 import assertifyStatement from './assertify-statement';
@@ -9,16 +8,11 @@ import { extractConfigFromState } from './config';
 const assertionBlockLabels = ['expect', 'then'];
 
 const plugin = (babel: { types: typeof BabelTypes }): PluginObj => {
-  const espowerVisitor = createEspowerVisitor(babel, {
-    embedAst: true,
-    patterns: ['assert(value)'],
-  });
-
   return {
     visitor: {
       LabeledStatement(path, state) {
         const config = extractConfigFromState(state);
-        const assertify = assertifyStatement(babel.types, config);
+        const assertify = assertifyStatement(babel, state, config);
 
         if (assertionBlockLabels.includes(path.node.label.name)) {
           const bodyPath = path.get('body') as NodePath<BabelTypes.Statement>;
@@ -32,11 +26,6 @@ const plugin = (babel: { types: typeof BabelTypes }): PluginObj => {
             default:
               assertify(bodyPath);
           }
-
-          if (config.powerAssert) {
-            // Now let espower generate nice power assertions for this labeled statement
-            espowerVisitor.visitor.Program(path, state);
-          }
         }
       },
     },

test/__snapshots__/power-assert.test.ts.snap

@@ -57,3 +57,17 @@ exports[`supports non-standard JSX syntax 1`] = `
   
   "
 `;
+
+exports[`works when using autoImport 1`] = `
+"  # test.js:1
+  
+  _assert(1 === 2)
+            |     
+            false 
+  
+  [number] 2
+  => 2
+  [number] 1
+  => 1
+  "
+`;

test/power-assert.test.ts

@@ -87,3 +87,15 @@ test('supports non-standard JSX syntax', () => {
     }),
   ).toThrowErrorMatchingSnapshot();
 });
+
+test('works when using autoImport', () => {
+  const { code } = transform(`expect: 1 === 2;`, {
+    plugins: [plugin],
+    presets: ['@babel/preset-env'],
+    filename: 'test.js',
+  });
+
+  expect(() =>
+    new Function('require', code as string)(require),
+  ).toThrowErrorMatchingSnapshot();
+});