mieszko4 · March 28, 2018 23:43 · Mar 28, 2018
diff --git a/PromiseDelayToDelay.codemod.js b/PromiseDelayToDelay.codemod.js
@@ -0,0 +1,53 @@
+module.exports = function (fileInfo, api) {
+  const j = api.jscodeshift;
+
+  const isPromiseDelay = (nodePath) => {
+    const { object, property } = nodePath.node.callee;
+
+    return object && object.name === 'Promise' && property && property.name === 'delay';
+  };
+
+  const isRequire = (nodePath, name) => {
+    if (nodePath.parent.node.type === 'Program') {
+      return j(nodePath)
+        .find(j.VariableDeclarator)
+        .filter((p) => {
+          const { id, init } = p.node;
+          return id.type === 'Identifier' && id.name === name &&
+            init.type === 'CallExpression' && init.callee.type === 'Identifier' &&
+            init.callee.name === 'require';
+        })
+        .size() > 0;
+    }
+
+    return false;
+  };
+
+  const transfromPromiseDelay = (nodePath) => {
+    const { node } = nodePath;
+
+    const idDelay = j.identifier('delay');
+    const newCallExpression = j.callExpression(idDelay, node.arguments);
+    j(nodePath).replaceWith(newCallExpression);
+  };
+
+  const output = j(fileInfo.source);
+
+  // replace Promise.delay to delay
+  const didItTransform = output.find(j.CallExpression)
+    .filter(isPromiseDelay)
+    .forEach(transfromPromiseDelay)
+    .size() > 0;
+
+  // add require
+  if (didItTransform) {
+    output
+      .find(j.VariableDeclaration)
+      .filter(p => isRequire(p, 'Promise'))
+      .forEach((nodePath) => {
+        j(nodePath).insertBefore('const delay = require(\'delay\');');
+      });
+  }
+
+  return didItTransform ? output.toSource() : null;
+};