fix: inline variable with multiple assignments (#121)

j4k0xb · Nov 2, 2024 · 2327e60 · 2327e60
1 parent 4fb9c6b
commit 2327e60
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Showing 2 changed files with 36 additions and 14 deletions.
diff --git a/packages/webcrack/src/ast-utils/inline.ts b/packages/webcrack/src/ast-utils/inline.ts
@@ -36,21 +36,29 @@ export function inlineVariable(
       ref.replaceWith(varDeclarator.init!);
     });
     binding.path.remove();
-  } else if (
-    unsafeAssignments &&
-    binding.constantViolations.length === 1 &&
-    assignmentMatcher.match(binding.constantViolations[0]?.node)
-  ) {
-    const assignment = binding
-      .constantViolations[0] as NodePath<t.AssignmentExpression>;
-    binding.referencePaths.forEach((ref) => {
-      ref.replaceWith(assignment.node.right);
-    });
-    if (assignment.parentPath.isExpressionStatement()) {
-      assignment.remove();
-    } else {
-      assignment.replaceWith(assignment.node.right);
+  } else if (unsafeAssignments && binding.constantViolations.length >= 1) {
+    const assignments = binding.constantViolations
+      .map((path) => path.node)
+      .filter((node) => assignmentMatcher.match(node));
+    if (!assignments.length) return;
+
+    function getNearestAssignment(location: number) {
+      return assignments.findLast((assignment) => assignment.start! < location);
+    }
+
+    for (const ref of binding.referencePaths) {
+      const assignment = getNearestAssignment(ref.node.start!);
+      if (assignment) ref.replaceWith(assignment.right);
     }
+
+    for (const path of binding.constantViolations) {
+      if (path.parentPath?.isExpressionStatement()) {
+        path.remove();
+      } else if (path.isAssignmentExpression()) {
+        path.replaceWith(path.node.right);
+      }
+    }
+
     binding.path.remove();
   }
 }

diff --git a/packages/webcrack/src/ast-utils/test/inline.test.ts b/packages/webcrack/src/ast-utils/test/inline.test.ts
@@ -31,6 +31,20 @@ test('inline variable with assignment', () => {
   expect(ast).toMatchInlineSnapshot(`let b = 1;`);
 });
 
+test('inline variable with multiple assignments', () => {
+  const ast = parse('let a; a = 1; let b = a; a = 2; let c = a; a = 3;');
+  traverse(ast, {
+    Program(path) {
+      const binding = path.scope.getBinding('a')!;
+      inlineVariable(binding, undefined, true);
+    },
+  });
+  expect(ast).toMatchInlineSnapshot(`
+    let b = 1;
+    let c = 2;
+  `);
+});
+
 test('inline variable with assignment in an expression', () => {
   const ast = parse('let a; x = a = 1; let b = a;');
   traverse(ast, {