Convert remaining files to TypeScript (graphql#658)

.eslintrc.yml

@@ -542,7 +542,8 @@ overrides:
       '@typescript-eslint/no-throw-literal': error
       '@typescript-eslint/no-type-alias': off # TODO consider
       '@typescript-eslint/no-unnecessary-boolean-literal-compare': error
-      '@typescript-eslint/no-unnecessary-condition': error
+      # FIXME: Disabled to enable checking conditions that would be prevented by types anyway
+      '@typescript-eslint/no-unnecessary-condition': off
       '@typescript-eslint/no-unnecessary-qualifier': error
       '@typescript-eslint/no-unnecessary-type-arguments': error
       '@typescript-eslint/no-unnecessary-type-assertion': error

.mocharc.yml

@@ -1,5 +1,4 @@
 throw-deprecation: true
 check-leaks: true
 require:
-  - '@babel/register'
-  - ts-node/register
+  - './resources/register.js'

cspell.json

@@ -22,6 +22,7 @@
     "serializable",
     "subcommand",
     "charsets",
+    "downlevel",
 
     // TODO: remove bellow words
     "Graphi", // GraphiQL

package.json

@@ -6,6 +6,13 @@
   "private": true,
   "main": "index.js",
   "types": "index.d.ts",
+  "typesVersions": {
+    "<3.8": {
+      "*": [
+        "ts3.4/*"
+      ]
+    }
+  },
   "sideEffects": false,
   "homepage": "https://github.com/graphql/express-graphql",
   "bugs": {
@@ -40,7 +47,7 @@
     "check:spelling": "cspell '**/*'",
     "check:integrations": "mocha --full-trace integrationTests/*-test.js",
     "build": "node resources/build.js",
-    "start": "node -r @babel/register examples/index.js"
+    "start": "node -r ./resources/register.js examples/index.ts"
   },
   "dependencies": {
     "accepts": "^1.3.7",
@@ -53,10 +60,13 @@
     "@babel/plugin-transform-flow-strip-types": "7.10.4",
     "@babel/preset-env": "7.10.4",
     "@babel/register": "7.10.4",
+    "@types/accepts": "1.3.5",
     "@types/body-parser": "1.19.0",
     "@types/chai": "4.2.11",
     "@types/connect": "3.4.33",
+    "@types/content-type": "1.1.3",
     "@types/express": "4.17.6",
+    "@types/http-errors": "1.6.3",
     "@types/mocha": "7.0.2",
     "@types/multer": "1.4.3",
     "@types/node": "14.0.14",
@@ -70,6 +80,7 @@
     "chai": "4.2.0",
     "connect": "3.7.0",
     "cspell": "4.0.63",
+    "downlevel-dts": "0.5.0",
     "eslint": "7.3.1",
     "eslint-plugin-flowtype": "5.2.0",
     "eslint-plugin-import": "2.22.0",

resources/build.js

@@ -6,29 +6,33 @@ const fs = require('fs');
 const path = require('path');
 const assert = require('assert');
 
-const babel = require('@babel/core');
+const ts = require('typescript');
+const { main: downlevel } = require('downlevel-dts');
 
+const tsConfig = require('../tsconfig.json');
+
+const {
+  transformLoadFileStaticallyFromNPM,
+} = require('./load-statically-from-npm');
 const { rmdirRecursive, readdirRecursive, showStats } = require('./utils');
 
 if (require.main === module) {
   rmdirRecursive('./dist');
   fs.mkdirSync('./dist');
 
   const srcFiles = readdirRecursive('./src', { ignoreDir: /^__.*__$/ });
-  for (const filepath of srcFiles) {
-    const srcPath = path.join('./src', filepath);
-    const destPath = path.join('./dist', filepath);
-
-    fs.mkdirSync(path.dirname(destPath), { recursive: true });
-    if (filepath.endsWith('.js')) {
-      fs.copyFileSync(srcPath, destPath + '.flow');
-
-      const cjs = babelBuild(srcPath, { envName: 'cjs' });
-      fs.writeFileSync(destPath, cjs);
-    } else if (filepath.endsWith('d.ts')) {
-      fs.copyFileSync(srcPath, destPath);
-    }
-  }
+  const { options } = ts.convertCompilerOptionsFromJson(
+    tsConfig.compilerOptions,
+    process.cwd(),
+  );
+  const program = ts.createProgram({
+    rootNames: srcFiles.map((filepath) => path.join('./src', filepath)),
+    options,
+  });
+  program.emit(undefined, undefined, undefined, undefined, {
+    after: [transformLoadFileStaticallyFromNPM],
+  });
+  downlevel('./dist', './dist/ts3.4');
 
   fs.copyFileSync('./LICENSE', './dist/LICENSE');
   fs.copyFileSync('./README.md', './dist/README.md');
@@ -40,10 +44,6 @@ if (require.main === module) {
   showStats();
 }
 
-function babelBuild(srcPath, options) {
-  return babel.transformFileSync(srcPath, options).code + '\n';
-}
-
 function buildPackageJSON() {
   const packageJSON = require('../package.json');
   delete packageJSON.private;

resources/load-statically-from-npm.js

@@ -4,9 +4,9 @@
 
 const fs = require('fs');
 
+const ts = require('typescript');
+
 /**
- * Eliminates function call to `invariant` if the condition is met.
- *
  * Transforms:
  *
  *  loadFileStaticallyFromNPM(<npm path>)
@@ -15,23 +15,19 @@ const fs = require('fs');
  *
  *  "<file content>"
  */
-module.exports = function inlineInvariant(context) {
-  return {
-    visitor: {
-      CallExpression(path) {
-        const { node } = path;
-
-        if (
-          node.callee.type === 'Identifier' &&
-          node.callee.name === 'loadFileStaticallyFromNPM'
-        ) {
-          const npmPath = node.arguments[0].value;
-          const filePath = require.resolve(npmPath);
-          const content = fs.readFileSync(filePath, 'utf-8');
-
-          path.replaceWith(context.types.stringLiteral(content));
-        }
-      },
-    },
+module.exports.transformLoadFileStaticallyFromNPM = function (context) {
+  return function visit(node) {
+    if (ts.isCallExpression(node)) {
+      if (
+        ts.isIdentifier(node.expression) &&
+        node.expression.text === 'loadFileStaticallyFromNPM'
+      ) {
+        const npmPath = node.arguments[0].text;
+        const filePath = require.resolve(npmPath);
+        const content = fs.readFileSync(filePath, 'utf-8');
+        return ts.createStringLiteral(content);
+      }
+    }
+    return ts.visitEachChild(node, visit, context);
   };
 };

resources/register.js

@@ -0,0 +1,11 @@
+'use strict';
+
+const {
+  transformLoadFileStaticallyFromNPM,
+} = require('./load-statically-from-npm');
+
+require('ts-node').register({
+  transformers: () => ({
+    after: [transformLoadFileStaticallyFromNPM],
+  }),
+});