Minimal backend typescript support (#3207)gh-1454

* minimal ts support

Co-authored-by: Matt Godbolt <matt@godbolt.org>

9 files changed, 131 insertions, 24 deletions

diff --git a/.eslintrc.yml b/.eslintrc.yml
index c65dcbb91..6f9cd59a5 100644
--- a/.eslintrc.yml
+++ b/.eslintrc.yml
@@ -7,6 +7,7 @@ plugins:
   - promise
   - sonarjs
   - unicorn
+  - '@typescript-eslint'
 extends:
   - ./.eslint-license-header.yml
   - eslint:recommended
@@ -14,6 +15,9 @@ extends:
   - plugin:node/recommended
   - plugin:unicorn/recommended
   - prettier
+  - plugin:@typescript-eslint/eslint-recommended
+  - plugin:@typescript-eslint/recommended
+  - plugin:import/typescript
 env:
   mocha: true
   node: true
@@ -28,6 +32,7 @@ rules:
   eqeqeq:
     - error
     - smart
+  import/default: off # fs-extra trips this. the ts compiler catches actual errors
   import/extensions: error
   import/first: error
   import/newline-after-import: error
@@ -36,6 +41,7 @@ rules:
   import/no-default-export: warn
   import/no-deprecated: warn
   import/no-mutable-exports: error
+  import/no-named-as-default-member: off  # Far too many things (express, morgan, fs) trip this
   import/no-self-import: error
   import/no-useless-path-segments: error
   import/no-webpack-loader-syntax: error
@@ -138,8 +144,17 @@ rules:
   unicorn/no-array-callback-reference: off
   unicorn/prefer-switch: off
   unicorn/no-static-only-class: off
+  unicorn/no-process-exit: off
+  '@typescript-eslint/no-empty-function': off
+  '@typescript-eslint/no-unused-vars': off
 parserOptions:
   sourceType: module
   ecmaVersion: 2020
 globals:
   BigInt: true
+settings:
+  node:
+    tryExtensions: [ .js, .ts ]
+  import/parsers:
+    "@typescript-eslint/parser": [ .ts, .tsx ]
+  import/resolver: "typescript"
diff --git a/.mocharc.yml b/.mocharc.yml
new file mode 100644
index 000000000..0fe58d691
--- /dev/null
+++ b/.mocharc.yml
@@ -0,0 +1,5 @@
+recursive: true
+require:
+  - esm
+  - ts-node/register
+  - source-map-support/register
diff --git a/.nycrc.yml b/.nycrc.yml
index e0174ab1d..749a1cbbf 100644
--- a/.nycrc.yml
+++ b/.nycrc.yml
@@ -1,6 +1,7 @@
 all: true
 include:
   - lib/**/*.js
+  - lib/**/*.ts
 exclude:
   - lib/handlers/asm-docs-amd64.js
   - lib/handlers/asm-docs-arm32.js
@@ -11,3 +12,5 @@ reporter:
   - lcov
 require:
   - esm
+  - source-map-support/register
+  - ts-node/register
\ No newline at end of file
diff --git a/Makefile b/Makefile
index 59422a8c9..b61ab4048 100644
--- a/Makefile
+++ b/Makefile
@@ -43,7 +43,7 @@ $(NODE_MODULES): package.json | node-installed
 WEBPACK:=./node_modules/webpack-cli/bin/cli.js
 $(WEBPACK): $(NODE_MODULES)
 
-lint: $(NODE_MODULES)  ## Checks if the source currently matches code conventions
+lint: $(NODE_MODULES) ts-compile ## Checks if the source currently matches code conventions
 	$(NPM) run lint
 
 lint-fix: $(NODE_MODULES)  ## Checks if everything matches code conventions & fixes those which are trivial to do so
@@ -72,20 +72,25 @@ clean:  ## Cleans up everything
 run: export NODE_ENV=production
 run: export WEBPACK_ARGS="--node-env=production"
 run: prereqs webpack  ## Runs the site normally
-	./node_modules/.bin/supervisor -w app.js,lib,etc/config,static/tsconfig.json -e 'js|ts|node|properties|yaml' --exec $(NODE) $(NODE_ARGS) -- -r esm ./app.js $(EXTRA_ARGS)
+	./node_modules/.bin/supervisor -w app.js,lib,etc/config,static/tsconfig.json -e 'js|ts|node|properties|yaml' --exec $(NODE) $(NODE_ARGS) -- -r esm -r ts-node/register ./app.js $(EXTRA_ARGS)
 
 dev: export NODE_ENV=development
 dev: prereqs ## Runs the site as a developer; including live reload support and installation of git hooks
-	./node_modules/.bin/supervisor -w app.js,lib,etc/config,static/tsconfig.json -e 'js|ts|node|properties|yaml' -n exit --exec $(NODE) $(NODE_ARGS) -- -r esm ./app.js $(EXTRA_ARGS)
+	./node_modules/.bin/supervisor -w app.js,lib,etc/config,static/tsconfig.json -e 'js|ts|node|properties|yaml' -n exit --exec $(NODE) $(NODE_ARGS) -- -r esm -r ts-node/register ./app.js $(EXTRA_ARGS)
 
 debug: export NODE_ENV=development
 debug: prereqs ## Runs the site as a developer with full debugging; including live reload support and installation of git hooks
-	./node_modules/.bin/supervisor -w app.js,lib,etc/config,static/tsconfig.json -e 'js|ts|node|properties|yaml' -n exit --inspect 9229 --exec $(NODE) $(NODE_ARGS) -- -r esm ./app.js --debug $(EXTRA_ARGS)
+	./node_modules/.bin/supervisor -w app.js,lib,etc/config,static/tsconfig.json -e 'js|ts|node|properties|yaml' -n exit --inspect 9229 --exec $(NODE) $(NODE_ARGS) -- -r esm -r ts-node/register ./app.js --debug $(EXTRA_ARGS)
+
+.PHONY: ts-compile
+# one day we'll put `--strict` in this
+ts-compile: prereqs
+	./node_modules/.bin/tsc
 
 HASH := $(shell git rev-parse HEAD)
 dist: export NODE_ENV=production
 dist: export WEBPACK_ARGS="--node-env=production"
-dist: prereqs webpack  ## Creates a distribution
+dist: prereqs webpack ts-compile  ## Creates a distribution
 	echo $(HASH) > out/dist/git_hash
 
 RELEASE_FILE_NAME=$(GITHUB_RUN_NUMBER)
diff --git a/app.js b/app.js
index a7631d53f..f5e52d9cb 100755
--- a/app.js
+++ b/app.js
@@ -1,7 +1,3 @@
-#!/usr/bin/env node
-// shebang interferes with license header plugin
-/* eslint-disable header/header */
-
 // Copyright (c) 2012, Compiler Explorer Authors
 // All rights reserved.
 //
diff --git a/lib/utils.js b/lib/utils.ts
index 97d864c34..fea13bc6e 100644
--- a/lib/utils.js
+++ b/lib/utils.ts
@@ -30,6 +30,18 @@ import fs from 'fs-extra';
 import quote from 'shell-quote';
 import _ from 'underscore';
 
+interface IResultLineTag {
+    line?: number;
+    column?: number;
+    file?: string;
+    text: string;
+}
+
+interface IResultLine {
+    text: string;
+    tag?: IResultLineTag;
+}
+
 const tabsRe = /\t/g;
 const lineRe = /\r?\n/;
 
@@ -58,7 +70,7 @@ export function splitLines(text) {
  * @param {eachLineFunc} func
  * @param {*} [context]
  */
-export function eachLine(text, func, context) {
+export function eachLine(text: string, func, context?): IResultLine[] {
     return _.each(splitLines(text), func, context);
 }
 
@@ -133,7 +145,7 @@ export function parseOutput(lines, inputFilename, pathPrefix) {
             line = maskRootdir(line);
         }
         if (line !== null) {
-            const lineObj = {text: line};
+            const lineObj: IResultLine = { text: line };
             const filteredline = line.replace(ansiColoursRe, '');
             let match = filteredline.match(re);
             if (match) {
@@ -172,7 +184,7 @@ export function parseRustOutput(lines, inputFilename, pathPrefix) {
     eachLine(lines, line => {
         line = _parseOutputLine(line, inputFilename, pathPrefix);
         if (line !== null) {
-            const lineObj = {text: line};
+            const lineObj: IResultLine = { text: line };
             const match = line.replace(ansiColoursRe, '').match(re);
 
             if (match) {
@@ -307,13 +319,13 @@ export function getHash(object, HashVersion = DefaultHash) {
  * @returns {glContents}
  */
 export function glGetMainContents(content) {
-    let contents = {editors: [], compilers: []};
+    const contents = { editors: [], compilers: [] };
     _.each(content, element => {
         if (element.type === 'component') {
             if (element.componentName === 'codeEditor') {
-                contents.editors.push({source: element.componentState.source, language: element.componentState.lang});
+                contents.editors.push({ source: element.componentState.source, language: element.componentState.lang });
             } else if (element.componentName === 'compiler') {
-                contents.compilers.push({compiler: element.componentState.compiler});
+                contents.compilers.push({ compiler: element.componentState.compiler });
             }
         } else {
             const subComponents = glGetMainContents(element.content);
@@ -459,7 +471,7 @@ export async function dirExists(dir) {
 export function countOccurrences(collection, item) {
     // _.reduce(collection, (total, value) => value === item ? total + 1 : total, 0) would work, but is probably slower
     let result = 0;
-    for (let element of collection) {
+    for (const element of collection) {
         if (element === item) {
             result++;
         }
diff --git a/package.json b/package.json
index 2abea5374..bfaccf5c6 100644
--- a/package.json
+++ b/package.json
@@ -149,15 +149,15 @@
   },
   "scripts": {
     "ci-lint": "eslint --format github .",
-    "ci-test": "nyc mocha --recursive",
+    "ci-test": "nyc npm run test",
     "lint": "eslint .",
     "lint-fix": "eslint --fix .",
     "test": "mocha --recursive",
     "check": "npm run lint && npm run test",
-    "dev": "cross-env NODE_ENV=DEV node -r esm app.js",
-    "debugger": "cross-env NODE_ENV=DEV node --inspect -r esm app.js --debug",
-    "debug": "cross-env NODE_ENV=DEV node -r esm app.js --debug",
-    "start": "webpack && cross-env NODE_ENV=LOCAL node -r esm app.js",
+    "dev": "cross-env NODE_ENV=DEV node -r esm -r ts-node/register app.js",
+    "debugger": "cross-env NODE_ENV=DEV node --inspect -r esm -r ts-node/register app.js --debug",
+    "debug": "cross-env NODE_ENV=DEV node -r esm -r ts-node/register app.js --debug",
+    "start": "webpack && cross-env NODE_ENV=LOCAL node -r esm -r ts-node/register app.js",
     "codecov": "codecov --disable=gcov",
     "sentry": "npx -p @sentry/cli sentry-cli",
     "update-browserslist": "npx browserslist@latest -- --update-db",
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 000000000..79d079aee
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,71 @@
+{
+  "include": ["lib/**/*"],
+  "compilerOptions": {
+    /* Visit https://aka.ms/tsconfig.json to read more about this file */
+
+    /* Basic Options */
+    // "incremental": true,                   /* Enable incremental compilation */
+    "target": "esnext" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */,
+    "module": "esnext" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */,
+    // "lib": [],                             /* Specify library files to be included in the compilation. */
+    // "allowJs": true,                       /* Allow javascript files to be compiled. */
+    // "checkJs": true,                       /* Report errors in .js files. */
+    // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
+    // "declaration": true,                   /* Generates corresponding '.d.ts' file. */
+    // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
+    // "sourceMap": true,                     /* Generates corresponding '.map' file. */
+    // "outFile": "./",                       /* Concatenate and emit output to single file. */
+    "outDir": "./out/app" /* Redirect output structure to the directory. */,
+    // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
+    // "composite": true,                     /* Enable project compilation */
+    // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
+    // "removeComments": true,                /* Do not emit comments to output. */
+    // "noEmit": true,                        /* Do not emit outputs. */
+    // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
+    // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
+    // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
+
+    /* Strict Type-Checking Options */
+    // "strict": true,                        /* Enable all strict type-checking options. */
+    // "noImplicitAny": true,                 /* Raise error on expressions and declarations with an implied 'any' type. */
+    // "strictNullChecks": true,              /* Enable strict null checks. */
+    // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
+    // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
+    // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
+    // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
+    // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
+
+    /* Additional Checks */
+    // "noUnusedLocals": true,                /* Report errors on unused locals. */
+    // "noUnusedParameters": true,            /* Report errors on unused parameters. */
+    // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
+    // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
+
+    /* Module Resolution Options */
+    "moduleResolution": "node" /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */,
+    // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
+    // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
+    // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
+    // "typeRoots": [],                       /* List of folders to include type definitions from. */
+    "typeRoots": ["./typings", "./node_modules/@types"],
+    // "types": [],                           /* Type declaration files to be included in compilation. */
+    // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
+    "esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */,
+    // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
+    // "allowUmdGlobalAccess": true,          /* Allow accessing UMD globals from modules. */
+
+    /* Source Map Options */
+    "sourceRoot": "/" /* Specify the location where debugger should locate TypeScript files instead of source locations. */,
+    // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
+    "inlineSourceMap": true /* Emit a single file with source maps instead of having a separate file. */,
+    // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
+
+    /* Experimental Options */
+    // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
+    // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
+
+    /* Advanced Options */
+    "skipLibCheck": true /* Skip type checking of declaration files. */,
+    "forceConsistentCasingInFileNames": true /* Disallow inconsistently-cased references to the same file. */
+  }
+}
diff --git a/webpack.config.esm.js b/webpack.config.esm.js
index 82f06d67b..464b8d2ff 100644
--- a/webpack.config.esm.js
+++ b/webpack.config.esm.js
@@ -31,7 +31,7 @@ import CssMinimizerPlugin from 'css-minimizer-webpack-plugin';
 import MiniCssExtractPlugin from 'mini-css-extract-plugin';
 import MonacoEditorWebpackPlugin from 'monaco-editor-webpack-plugin';
 import TerserPlugin from 'terser-webpack-plugin';
-import webpack from 'webpack';
+import {HotModuleReplacementPlugin, ProvidePlugin} from 'webpack';
 import {WebpackManifestPlugin} from 'webpack-manifest-plugin';
 
 const __dirname = path.resolve(path.dirname(fileURLToPath(import.meta.url)));
@@ -57,7 +57,7 @@ const plugins = [
             },
         ],
     }),
-    new webpack.ProvidePlugin({
+    new ProvidePlugin({
         $: 'jquery',
         jQuery: 'jquery',
     }),
@@ -71,7 +71,7 @@ const plugins = [
 ];
 
 if (isDev) {
-    plugins.push(new webpack.HotModuleReplacementPlugin());
+    plugins.push(new HotModuleReplacementPlugin());
 }
 
 // eslint-disable-next-line import/no-default-export