Add support for TypeScript (#260)

Add build system infrastructure to slowly migrate all code to
TypeScript.

We need to immediately migrate all imports/exports to ES6 syntax
because otherwise the module does not compile at all and the
library exports are completely broken.

.eslintignore

@@ -1 +1,5 @@
 lib/grammar.js
+lib/nn-syntax/parser.js
+node_modules
+dist
+coverage

.eslintrc.yml

@@ -1,31 +1,44 @@
 env:
   es6: true
   node: true
+parser: '@typescript-eslint/parser'
+plugins:
+  - '@typescript-eslint'
 parserOptions:
   ecmaVersion: 2018
-extends: 'eslint:recommended'
+extends:
+  - 'eslint:recommended'
+  - 'plugin:@typescript-eslint/recommended'
 rules:
   indent: off
   no-console: off
   no-fallthrough: off
-  linebreak-style:
-    - error
-    - unix
-  semi:
+  '@typescript-eslint/no-empty-function': off
+  require-atomic-updates: off
+  no-lonely-if: off
+  arrow-body-style: off
+
+  # temporary until migration is complete
+  '@typescript-eslint/no-this-alias': off
+
+  # correctness checks
+  strict:
     - error
-    - always
+    - global
   consistent-return: error
-  curly:
-    - error
-    - multi-or-nest
-    - consistent
+  array-callback-return: error
   eqeqeq:
     - error
     - always
-  no-unused-vars:
+  no-var: error
+  no-unused-vars: off
+  '@typescript-eslint/no-unused-vars':
     - error
     -
+      varsIgnorePattern: _
       args: none
+  no-shadow-restricted-names: error
+  no-promise-executor-return: error
   no-case-declarations: warn
   no-eval: error
   no-proto: error
@@ -35,16 +48,60 @@ rules:
   no-useless-call: warn
   no-useless-return: warn
   no-void: error
+  no-self-compare: error
   prefer-promise-reject-errors: error
-  strict:
-    - error
-    - global
   no-label-var: error
-  no-lonely-if: off
   no-new-object: error
-  arrow-body-style: off
+  no-invalid-this: error
+  prefer-arrow-callback: warn
+  prefer-numeric-literals: error
+  no-constructor-return: error
+  no-new-wrappers: error
+  no-return-await: warn
+  no-unused-expressions: warn
+
+  # code style
+  linebreak-style:
+    - error
+    - unix
+  semi:
+    - error
+    - always
+  curly:
+    - error
+    - multi-or-nest
+    - consistent
+  dot-location:
+    - error
+    - property
   arrow-parens:
     - error
     - always
-  prefer-arrow-callback: warn
-  prefer-numeric-literals: error
+  block-spacing: error
+  computed-property-spacing: error
+  func-call-spacing: error
+  keyword-spacing:
+    - error
+    -
+      overrides:
+        catch:
+          before: true
+          after: false
+  space-before-function-paren:
+    - error
+    -
+      anonymous: never
+      named: never
+      asyncArrow: always
+  generator-star-spacing:
+    - error
+    -
+      anonymous:
+        before: false
+        after: false
+      named:
+        before: false
+        after: true
+      method:
+        before: false
+        after: false

.gitignore

@@ -2,6 +2,7 @@
 .DS_Store
 node_modules/
 coverage/
+dist/
 .nyc_output/
 po/thingtalk.pot
 po/*.mo

Makefile

@@ -1,6 +1,5 @@
 %.js : %.lr tools/generate-parser/*.js tools/generate-parser/grammar.js
-	node tools/generate-parser $@ $<
-	node -c $@
+	ts-node tools/generate-parser $@ $<
 
 %.js : %.pegjs
 	pegjs -o $@ $<
@@ -15,7 +14,11 @@ all = \
 	lib/grammar.js \
 	test/test_sr_parser_generator.js
 
-all: $(all)
+dist: lib lib/* lib/ast/* lib/builtin/* lib/compiler/* lib/nn-syntax/* lib/runtime/* $(all)
+	tsc --build tsconfig.json
+	touch $@
+
+all: dist
 
 lib/grammar.js : lib/grammar.pegjs
 	pegjs --allowed-start-rules input,type_ref,permission_rule -o $@ $<

lib/ast/api.js

@@ -17,14 +17,16 @@
 // limitations under the License.
 //
 // Author: Giovanni Campagna <gcampagn@cs.stanford.edu>
-"use strict";
 
-const assert = require('assert');
+import assert from 'assert';
 
-const Ast = require('.');
+import { Selector } from './expression';
+import { Action } from './primitive';
+import { ClassDef } from './class_def';
+import { Statement, Program, Library, Example } from './program';
 
-const DeclarationProto = Ast.Statement.Declaration.prototype;
-const ExampleProto = Ast.Example.prototype;
+const DeclarationProto = Statement.Declaration.prototype;
+const ExampleProto = Example.prototype;
 
 
 // utilities
@@ -37,9 +39,9 @@ const ExampleProto = Ast.Example.prototype;
  * @alias Ast.notifyAction
  * @deprecated Use {@link Ast.Action.notifyAction} instead.
  */
-module.exports.notifyAction = function notifyAction(what) {
-    return Ast.Action.notifyAction(what);
-};
+export function notifyAction(what) {
+    return Action.notifyAction(what);
+}
 
 /**
  * Convert a manifest to a ThingTalk library.
@@ -50,10 +52,9 @@ module.exports.notifyAction = function notifyAction(what) {
  * @deprecated Manifests are deprecated and should not be used. Use .tt files instead.
  * @alias Ast.fromManifest
  */
-function fromManifest(kind, manifest) {
-    return new Ast.Library(null, [Ast.ClassDef.fromManifest(kind, manifest)], []);
+export function fromManifest(kind, manifest) {
+    return new Library(null, [ClassDef.fromManifest(kind, manifest)], []);
 }
-module.exports.fromManifest = fromManifest;
 
 /**
  * Convert a ThingTalk library to a manifest.
@@ -63,13 +64,14 @@ module.exports.fromManifest = fromManifest;
  * @deprecated Manifests are deprecated and should not be used. Use .tt files instead.
  * @alias Ast.toManifest
  */
-function toManifest(meta) {
-    assert(meta instanceof Ast.Library);
+export function toManifest(meta) {
+    assert(meta instanceof Library);
     return meta.classes[0].toManifest();
 }
-module.exports.toManifest = toManifest;
 
 function declarationLikeToProgram() {
+    /* eslint no-invalid-this: off */
+
     const nametoslot = {};
 
     let i = 0;
@@ -78,14 +80,14 @@ function declarationLikeToProgram() {
 
     let program;
     if (this.type === 'action') {
-        program = new Ast.Program(null, [], [],
-            [new Ast.Statement.Command(null, null, [this.value.clone()])], null);
+        program = new Program(null, [], [],
+            [new Statement.Command(null, null, [this.value.clone()])], null);
     } else if (this.type === 'query') {
-        program = new Ast.Program(null, [], [],
-            [new Ast.Statement.Command(null, this.value.clone(), [Ast.Action.notifyAction()])], null);
+        program = new Program(null, [], [],
+            [new Statement.Command(null, this.value.clone(), [Action.notifyAction()])], null);
     } else if (this.type === 'stream') {
-        program = new Ast.Program(null, [], [],
-            [new Ast.Statement.Rule(null, this.value.clone(), [Ast.Action.notifyAction()])], null);
+        program = new Program(null, [], [],
+            [new Statement.Rule(null, this.value.clone(), [Action.notifyAction()])], null);
     } else {
         program = this.value.clone();
     }
@@ -100,7 +102,7 @@ function declarationLikeToProgram() {
     }
 
     for (let slot of program.iterateSlots2()) {
-        if (slot instanceof Ast.Selector)
+        if (slot instanceof Selector)
             continue;
         recursiveHandleSlot(slot.get());
     }

lib/ast/base.js

@@ -17,10 +17,9 @@
 // limitations under the License.
 //
 // Author: Silei Xu <silei@cs.stanford.edu>
-"use strict";
 
-const assert = require('assert');
-const NodeVisitor = require('./visitor');
+import assert from 'assert';
+import NodeVisitor from './visitor';
 
 /**
  * A single point in the source code input stream.
@@ -50,7 +49,7 @@ const NodeVisitor = require('./visitor');
  * @alias Ast~Node
  * @abstract
  */
-module.exports = class Node {
+export default class Node {
     /**
      * Construct a new AST node.
      *
@@ -155,4 +154,4 @@ module.exports = class Node {
         this.visit(visitor);
         return buffer;
     }
-};
+}