feat: req.param transform (#5)

* start transform for req.param method to object

* replace callExpression with memberExpression for req.param

* add tests for req.param nested object keys

* fix lint

---------

Co-authored-by: Filip Kudła <[email protected]>

Author: kjugi

config.ts

@@ -9,9 +9,9 @@ export const TRANSFORM_OPTIONS = [
     value: 'pluralized-methods',
     version: '5.0.0',
   },
-  { 
-    description: 'Transform the deprecated signatures in Express v4', 
-    value: 'v4-deprecated-signatures', 
-    version: '5.0.0'
+  {
+    description: 'Transform the deprecated signatures in Express v4',
+    value: 'v4-deprecated-signatures',
+    version: '5.0.0',
   },
 ]

transforms/__test__/req-param.spec.ts

@@ -0,0 +1,3 @@
+import { testSpecBuilder } from './util'
+
+testSpecBuilder('req-param')

transforms/__testfixtures__/req-param/req-param.input.ts

@@ -0,0 +1,39 @@
+import express from "express";
+
+const app = express();
+
+app.get("/", function (req, res) {
+  const reqBody = req.param('body');
+  const reqQuery = req.param('query');
+  const reqQueryTest = req.param('query').test;
+  const reqOther = req.param('other');
+  const reqOtherNested = req.param('other').nested;
+});
+
+app.get("/", function (request, response) {
+  const reqBody = request.param('body');
+  const reqQuery = request.param('query');
+  const reqQueryTest = request.param('query').test;
+  const reqOther = request.param('other');
+  const reqOtherNested = request.param('other').nested;
+});
+
+app.get("/", (req, res) => {
+  const reqBody = req.param('body');
+  const reqQuery = req.param('query');
+  const reqQueryTest = req.param('query').test;
+  const reqOther = req.param('other');
+  const reqOtherNested = req.param('other').nested;
+});
+
+app.get("/", (request, response) => {
+  const reqBody = request.param('body');
+  const reqQuery = request.param('query');
+  const reqQueryTest = request.param('query').test;
+  const reqOther = request.param('other');
+  const reqOtherNested = request.param('other').nested;
+});
+
+app.param(function () {
+    // my important logic
+})

transforms/__testfixtures__/req-param/req-param.output.ts

@@ -0,0 +1,39 @@
+import express from "express";
+
+const app = express();
+
+app.get("/", function (req, res) {
+  const reqBody = req.body;
+  const reqQuery = req.query;
+  const reqQueryTest = req.query.test;
+  const reqOther = req.params.other;
+  const reqOtherNested = req.params.other.nested;
+});
+
+app.get("/", function (request, response) {
+  const reqBody = request.body;
+  const reqQuery = request.query;
+  const reqQueryTest = request.query.test;
+  const reqOther = request.params.other;
+  const reqOtherNested = request.params.other.nested;
+});
+
+app.get("/", (req, res) => {
+  const reqBody = req.body;
+  const reqQuery = req.query;
+  const reqQueryTest = req.query.test;
+  const reqOther = req.params.other;
+  const reqOtherNested = req.params.other.nested;
+});
+
+app.get("/", (request, response) => {
+  const reqBody = request.body;
+  const reqQuery = request.query;
+  const reqQueryTest = request.query.test;
+  const reqOther = request.params.other;
+  const reqOtherNested = request.params.other.nested;
+});
+
+app.param(function () {
+    // my important logic
+})

transforms/param.ts renamed to transforms/app-param.ts

@@ -9,11 +9,11 @@ export default function transformer(file: FileInfo, _api: API): string {
       .find(CallExpression, {
         callee: {
           property: {
-            name: 'json',
+            name: 'param',
           },
         },
       })
-      // TODO: app.param(fn): This method has been deprecated. Instead, access parameters directly via req.params, or use req.body or req.query as needed.
+      // TODO: The app.param(fn) signature was used for modifying the behavior of the app.param(name, fn) function
       // Add comment line before with this information
       .toSource()
   )

transforms/req-param.ts

@@ -0,0 +1,44 @@
+import type { API, FileInfo } from 'jscodeshift'
+import { CallExpression, identifier, memberExpression, withParser } from 'jscodeshift'
+import { recursiveParent } from '../utils/recursiveParent'
+
+export default function transformer(file: FileInfo, _api: API): string {
+  const parser = withParser('ts')
+
+  return parser(file.source)
+    .find(CallExpression, {
+      callee: {
+        property: {
+          name: 'param',
+        },
+      },
+    })
+    .filter((path) => Boolean(recursiveParent(path.parentPath)))
+    .replaceWith((path) => {
+      const pathArguments = path.node.arguments
+
+      if (pathArguments.length > 1) {
+        return path
+      }
+
+      if (pathArguments[0].type === 'StringLiteral') {
+        if (pathArguments[0].value === 'query') {
+          // convert to req.query
+          return memberExpression(identifier(recursiveParent(path.parentPath) || 'req'), identifier('query'))
+        }
+        if (pathArguments[0].value === 'body') {
+          // convert to req.body
+          return memberExpression(identifier(recursiveParent(path.parentPath) || 'req'), identifier('body'))
+        }
+
+        // convert to req.params.[value]
+        return memberExpression(
+          memberExpression(identifier(recursiveParent(path.parentPath) || 'req'), identifier('params')),
+          identifier(pathArguments[0].value),
+        )
+      }
+
+      return path
+    })
+    .toSource()
+}