wip

Author: alexreardon

community/memoize-one/src/5.0.0/transform.spec.ts

@@ -35,7 +35,7 @@ describe('memoize-one@5.0.0 transform', () => {
     );
   });
 
-  it('should wrap inline equality functions', () => {
+  it.only('should wrap inline equality functions', () => {
     const result = applyTransform(
       transformer,
       format(`

community/memoize-one/src/5.0.0/transform.ts

@@ -1,3 +1,7 @@
+import {
+  hasImportDeclaration,
+  getDefaultImportSpecifierName,
+} from '@codeshift/utils';
 import { API, FileInfo, Options } from 'jscodeshift';
 
 export default function transformer(
@@ -15,10 +19,69 @@ export default function transformer(
    * See this page for more information:
    * https://codeshiftcommunity.github.io/CodeshiftCommunity/docs/your-first-codemod#output
    */
-  if (true) {
+  if (!hasImportDeclaration(j, source, 'memoize-one')) {
     return file.source;
   }
 
+  const importName = getDefaultImportSpecifierName(j, source, 'memoize-one');
+
+  source
+    .find(j.CallExpression)
+    // looking for calls to memoize-one
+    .filter(
+      call =>
+        call.value.callee.type === 'Identifier' &&
+        call.value.callee.name === importName,
+    )
+    // looking for calls with a custom equality function
+    // .filter(call => call.value.arguments.length === 2)
+    .forEach(call => {
+      const [first, second] = call.value.arguments;
+      if (second == null) {
+        return;
+      }
+      if (second.type === 'FunctionExpression') {
+        const customEqualityFn = j.arrowFunctionExpression(
+          [j.identifier('newArgs'), j.identifier('lastArgs')],
+          j.blockStatement([
+            j.ifStatement(
+              j.binaryExpression(
+                '!==',
+                j.memberExpression(
+                  j.identifier('newArgs'),
+                  j.identifier('length'),
+                ),
+                j.memberExpression(
+                  j.identifier('lastArgs'),
+                  j.identifier('length'),
+                ),
+              ),
+              j.returnStatement(j.booleanLiteral(false)),
+            ),
+            j.returnStatement(j.booleanLiteral(true)),
+          ]),
+        );
+
+        // (newArgs, lastArgs) => {
+        //   if (newArgs.length !== lastArgs.length) {
+        //     return false;
+        //   }
+
+        //   return newArgs.every((newArg, index) =>
+        //     isEqual(newArg, lastArgs[index]),
+        //   );
+        // };
+
+        call.value.arguments = [first, customEqualityFn];
+        // console.log('FunctionExpression', call);
+        // call.replace(j.functionExpression([first, 'hi']));
+        return;
+      }
+
+      if (second.type === 'Identifier') {
+      }
+    });
+
   /**
    * Codemod logic goes here 👇
    * -----
@@ -28,7 +91,7 @@ export default function transformer(
    * See this page for more information:
    * https://codeshiftcommunity.github.io/CodeshiftCommunity/docs/authoring#motions
    */
-  source.findVariableDeclarators('foo').renameTo('bar');
+  // source.findVariableDeclarators('foo').renameTo('bar');
 
   /**
    * Return your modified AST here 👇