feat(parser): implemented dynamic import (stage 3)

README.md

@@ -18,7 +18,7 @@ A 100% compliant, self-hosted javascript parser with high focus on both performa
 * Emits an ESTree-compatible abstract syntax tree.
 * No backtracking
 * Reduced memory usage
-* Very well tested (~71k unit tests with full code coverage))
+* Very well tested (~73 000 unit tests with full code coverage))
 * Lightweight - ~71 KB minified
 
 ## ESNext features

package.json

@@ -1,6 +1,6 @@
 {
   "name": "meriyah",
-  "version": "0.1.13",
+  "version": "0.1.14",
   "description": "A 100% compliant, self-hosted javascript parser with high focus on both performance and stability",
   "main": "dist/meriyah.umd.js",
   "module": "dist/meriyah.esm.js",

src/errors.ts

@@ -154,7 +154,9 @@ export const enum Errors {
   InvalidKeyToken,
   LabelRedeclaration,
   InvalidNestedStatement,
-  UnknownLabel
+  UnknownLabel,
+  InvalidImportTail,
+  ImportNotOneArg
 }
 
 /*@internal*/
@@ -322,7 +324,9 @@ export const errorMessages: {
   [Errors.InvalidKeyToken]: 'Invalid key token',
   [Errors.LabelRedeclaration]: "Label '%0' has already been declared",
   [Errors.InvalidNestedStatement]: 'continue statement must be nested within an iteration statement',
-  [Errors.UnknownLabel]: "Undefined label '%0'"
+  [Errors.UnknownLabel]: "Undefined label '%0'",
+  [Errors.InvalidImportTail]: 'Trailing comma is disallowed inside import(...) arguments',
+  [Errors.ImportNotOneArg]: 'import() requires exactly one argument'
 };
 
 export class ParseError extends SyntaxError {

src/estree.ts

@@ -32,6 +32,7 @@ interface T_Expression {
   UnaryExpression: UnaryExpression;
   UpdateExpression: UpdateExpression;
   BinaryExpression: BinaryExpression;
+  ImportExpression: ImportExpression;
   AssignmentExpression: AssignmentExpression;
   LogicalExpression: LogicalExpression;
   MemberExpression: MemberExpression;
@@ -424,15 +425,15 @@ export interface ConditionalExpression extends _Expression<'ConditionalExpressio
   consequent: Expression;
 }
 
-interface BaseCallExpression extends _Expression<'ThisExObjectExpressionpression'> {
-  callee: Expression | Super;
-  arguments: Array<Expression | SpreadElement>;
-}
-
 export interface CallExpression extends _Expression<'CallExpression'> {
-  callee: Expression | Super;
+  callee: Expression | Import | Super;
   arguments: (Expression | SpreadElement)[];
 }
+
+export interface Import extends _Node<'Import'> {}
+
+export interface ImportExpression extends _Expression<'Import'> {}
+
 export interface NewExpression extends _Expression<'NewExpression'> {
   callee: Expression;
   arguments: (Expression | SpreadElement)[];

src/lexer/comments.ts

@@ -4,17 +4,22 @@ import { Token } from '../token';
 import { ParserState, Flags } from '../common';
 import { report, Errors } from '../errors';
 
+/**
+ * Skips BOM and hasbang (stage 3)
+ *
+ * @param parser  Parser object
+ */
 export function skipHashBang(parser: ParserState): void {
   let index = parser.index;
-  if (parser.index === parser.source.length) return;
+  if (index === parser.length) return;
   if (parser.currentCodePoint === Chars.ByteOrderMark) {
-    parser.currentCodePoint = parser.source.charCodeAt(index++);
+    parser.currentCodePoint = parser.source.charCodeAt(++index);
     parser.index = index;
   }
 
-  if (index < parser.source.length && parser.source.charCodeAt(index) === Chars.Hash) {
+  if (index < parser.length && parser.source.charCodeAt(index) === Chars.Hash) {
     index++;
-    if (index < parser.source.length && parser.source.charCodeAt(index) === Chars.Exclamation) {
+    if (index < parser.length && parser.source.charCodeAt(index) === Chars.Exclamation) {
       parser.index = index + 1;
       parser.currentCodePoint = parser.source.charCodeAt(parser.index);
       skipSingleLineComment(parser);
@@ -24,6 +29,11 @@ export function skipHashBang(parser: ParserState): void {
   }
 }
 
+/**
+ * Skips single line comment
+ *
+ * @param parser  Parser object
+ */
 export function skipSingleLineComment(parser: ParserState): Token {
   while (parser.index < parser.length) {
     if (
@@ -37,6 +47,11 @@ export function skipSingleLineComment(parser: ParserState): Token {
   return Token.WhiteSpace;
 }
 
+/**
+ * Skips multiline comment
+ *
+ * @param parser  Parser object
+ */
 export function skipMultiLineComment(parser: ParserState): any {
   while (parser.index < parser.length) {
     while (CharTypes[parser.currentCodePoint] & CharFlags.Asterisk) {

src/meriyah.ts

@@ -23,4 +23,4 @@ export function parse(source: string, options: Options | void): ESTree.Program {
   return parseSource(source, options, Context.None);
 }
 
-export const version = '0.0.1';
+export const version = '0.1.14';