Converted to ESM + added dist script for CJS support

.gitignore

@@ -2,6 +2,10 @@
 node_modules
 npm-debug.log
 
+# Built files for commonJS portability
+index.cjs
+voidElements.cjs
+
 # Built package
 /*.tgz
 

.mocharc.js → .mocharc.cjs

@@ -1,5 +1,3 @@
-"use strict";
-
 process.env.NODE_ENV = "test";
 
 const nock = require("nock");

CHANGELOG.md

@@ -8,6 +8,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Moved to esm. Backwards compatible with cjs. Breaks backwards compatibility if a cjs project requires anything
+ but the index or lib/voidElements as these are the only exposed as cjs.
+
 ## [2.5.0] - 2023-06-01
 
 - Add support for `setheader` attribute on `<esi:eval />` and `<esi:include />`

index.js

@@ -1,11 +1,11 @@
-"use strict";
+import { pipeline, Readable } from "stream";
 
-const { pipeline, Readable } = require("stream");
-const ESI = require("./lib/ESI");
-const HTMLStream = require("@bonniernews/atlas-html-stream");
-const HTMLWriter = require("./lib/HTMLWriter");
+import HTMLStream from "@bonniernews/atlas-html-stream";
 
-module.exports = {
+import ESI from "./lib/ESI.js";
+import HTMLWriter from "./lib/HTMLWriter.js";
+
+export {
  ESI,
  HTMLWriter,
  parse,

lib/ESI.js

@@ -1,13 +1,11 @@
-"use strict";
+import ESIEvaluator from "./ESIEvaluator.js";
+import ListenerContext from "./ListenerContext.js";
+import ESIBase from "./ESIBase.js";
 
-const ESIEvaluator = require("./ESIEvaluator");
-const ListenerContext = require("./ListenerContext");
-const ESIBase = require("./ESIBase");
-
-module.exports = class ESI extends ESIBase {
+export default class ESI extends ESIBase {
  constructor(options) {
  const evaluator = new ESIEvaluator(new ListenerContext(options));
  super(evaluator);
  this.context.emitter = this;
  }
-};
+}

lib/ESIBase.js

@@ -1,8 +1,6 @@
-"use strict";
+import { Transform } from "stream";
 
-const { Transform } = require("stream");
-
-module.exports = class ESIBase extends Transform {
+export default class ESIBase extends Transform {
  constructor(evaluator) {
  super({ objectMode: true });
  this.evaluator = evaluator;
@@ -17,4 +15,4 @@ module.exports = class ESIBase extends Transform {
  return this.evaluator.onclosetag(name, next);
  }
  }
-};
+}

lib/ESIEvaluator.js

@@ -1,10 +1,10 @@
 /* eslint-disable no-use-before-define */
-"use strict";
+import { pipeline, Readable } from "stream";
 
-const { assign, test, replace } = require("./evaluateExpression");
-const { pipeline, Readable } = require("stream");
-const ESIBase = require("./ESIBase");
-const HTMLStream = require("@bonniernews/atlas-html-stream");
+import HTMLStream from "@bonniernews/atlas-html-stream";
+
+import { assign, test, replace } from "./evaluateExpression.js";
+import ESIBase from "./ESIBase.js";
 
 class ESITag {
  constructor(context) {
@@ -276,7 +276,7 @@ const EsiTags = {
  "esi:foreach": ESIForEach,
 };
 
-class ESIEvaluator {
+export default class ESIEvaluator {
  constructor(context) {
  this.context = context;
  }
@@ -381,5 +381,3 @@ class ESIEvaluator {
  }, {});
  }
 }
-
-module.exports = ESIEvaluator;

lib/HTMLWriter.js

@@ -1,9 +1,8 @@
-"use strict";
+import { Transform } from "stream";
 
-const { chunkToMarkup } = require("./markup");
-const { Transform } = require("stream");
+import { chunkToMarkup } from "./markup.js";
 
-module.exports = class HTMLWriter extends Transform {
+export default class HTMLWriter extends Transform {
  constructor() {
  super({ writableObjectMode: true });
  }
@@ -16,4 +15,4 @@ module.exports = class HTMLWriter extends Transform {
  }
  return next(null, markup);
  }
-};
+}

lib/ListenerContext.js

@@ -1,11 +1,11 @@
-"use strict";
+import { EventEmitter } from "events";
 
-const { chunkToMarkup } = require("./markup");
-const { EventEmitter } = require("events");
-const { replace } = require("./evaluateExpression");
-const request = require("got");
+import request from "got";
 
-module.exports = class ListenerContext {
+import { chunkToMarkup } from "./markup.js";
+import { replace } from "./evaluateExpression.js";
+
+export default class ListenerContext {
  constructor(options = {}, emitter) {
  this.options = options;
  this.emitter = emitter || new EventEmitter();
@@ -115,7 +115,7 @@ module.exports = class ListenerContext {
  return { [key]: replace(val, self) };
  }
  }
-};
+}
 
 function buildHeaderVariables(headers) {
  if (!headers) return {};

lib/evaluateExpression.js

@@ -1,24 +1,16 @@
-"use strict";
+import evaluate from "./expression/evaluate.js";
+import { parse, split } from "./expression/parser.js";
 
-const evaluate = require("./expression/evaluate");
-const { parse, split } = require("./expression/parser");
-
-module.exports = {
- assign,
- test,
- replace,
-};
-
-function assign(value, context) {
+export function assign(value, context) {
  if (value === "true" || value === "false") return value;
  return evaluate(parse(value), context);
 }
 
-function test(expression, context) {
+export function test(expression, context) {
  return evaluate(parse(expression), context);
 }
 
-function replace(text, context) {
+export function replace(text, context) {
  if (!text) return;
 
  const expressions = split(text);

lib/expression/evaluate.js

@@ -1,8 +1,8 @@
 /* eslint-disable camelcase */
-"use strict";
 
-const crypto = require("crypto");
-const ent = require("ent");
+import crypto from "crypto";
+
+import ent from "ent";
 
 class Evaluator {
  constructor(context) {
@@ -205,9 +205,9 @@ class Evaluator {
  }
 }
 
-module.exports = function evaluate(ast, context) {
+export default function evaluate(ast, context) {
  return new Evaluator(context).execute(ast.type, ast);
-};
+}
 
 function castRight(left, right) {
  switch (typeof left) {

lib/expression/lexer.js

@@ -1,6 +1,22 @@
 /* eslint-disable prefer-template */
 
-"use strict";
+import {
+ ARRAY,
+ BINARY,
+ BLOCK,
+ BOOLEAN,
+ ENDMARK,
+ FUNCTION,
+ IDENTIFIER,
+ IDENTIFIER_CHARS,
+ LITERAL,
+ LOGICAL,
+ MEMBER,
+ NUMBER,
+ OBJECT,
+ UNARY,
+ WHITESPACE,
+} from "./types.js";
 
 const oneCharacterSymbols = "=()<>|*+-&{}/%,]:";
 const twoCharacterSymbols = [
@@ -18,24 +34,6 @@ const NUMBERS = "0123456789";
 const NUMBER_STARTCHARS = `-${NUMBERS}`;
 const NUMBER_CHARS = NUMBER_STARTCHARS + ".";
 
-const {
- ARRAY,
- BINARY,
- BLOCK,
- BOOLEAN,
- ENDMARK,
- FUNCTION,
- IDENTIFIER,
- IDENTIFIER_CHARS,
- LITERAL,
- LOGICAL,
- MEMBER,
- NUMBER,
- OBJECT,
- UNARY,
- WHITESPACE,
-} = require("./types");
-
 class EsiSyntaxError extends SyntaxError {
  constructor(message, source, column) {
  super(message);
@@ -208,7 +206,7 @@ class Token {
  }
 }
 
-class Lexer {
+export class Lexer {
  constructor(str, columnOffset, line) {
  this.str = str;
  this.scanner = new Scanner(str);
@@ -457,5 +455,3 @@ class Lexer {
  throw err;
  }
 }
-
-module.exports = { Lexer };

lib/expression/parser.js

@@ -1,9 +1,7 @@
 /* eslint-disable prefer-template */
-"use strict";
 
-const { Lexer } = require("./lexer");
-
-const {
+import { Lexer } from "./lexer.js";
+import {
  ARRAY,
  BINARY,
  BLOCK,
@@ -17,12 +15,7 @@ const {
  OBJECT,
  UNARY,
  WHITESPACE,
-} = require("./types");
-
-module.exports = {
- parse,
- split,
-};
+} from "./types.js";
 
 class AST {
  constructor() {
@@ -376,7 +369,7 @@ class Parser {
  }
 }
 
-function parse(input, columnOffset) {
+export function parse(input, columnOffset) {
  if (!input) return;
  input = input.trim();
 
@@ -389,7 +382,7 @@ function parse(input, columnOffset) {
  return ast.tree;
 }
 
-function split(input) {
+export function split(input) {
  const lines = input.split("\n");
 
  return lines.reduce((result, str, idx) => {

lib/expression/types.js

@@ -1,20 +1,16 @@
-"use strict";
-
-module.exports = {
- ARRAY: "ArrayExpression",
- BINARY: "BinaryExpression",
- BLOCK: "BlockStatement",
- BOOLEAN: "Boolean",
- ENDMARK: "EOL",
- EXPRESSION: "Expression",
- FUNCTION: "CallExpression",
- IDENTIFIER: "Identifier",
- LITERAL: "Literal",
- LOGICAL: "LogicalExpression",
- MEMBER: "MemberExpression",
- NUMBER: "Number",
- OBJECT: "ObjectExpression",
- UNARY: "UnaryExpression",
- WHITESPACE: "Space",
- IDENTIFIER_CHARS: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_",
-};
+export const ARRAY = "ArrayExpression";
+export const BINARY = "BinaryExpression";
+export const BLOCK = "BlockStatement";
+export const BOOLEAN = "Boolean";
+export const ENDMARK = "EOL";
+export const EXPRESSION = "Expression";
+export const FUNCTION = "CallExpression";
+export const IDENTIFIER = "Identifier";
+export const LITERAL = "Literal";
+export const LOGICAL = "LogicalExpression";
+export const MEMBER = "MemberExpression";
+export const NUMBER = "Number";
+export const OBJECT = "ObjectExpression";
+export const UNARY = "UnaryExpression";
+export const WHITESPACE = "Space";
+export const IDENTIFIER_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_";

lib/markup.js

@@ -1,16 +1,11 @@
-"use strict";
+import { selfClosingElements, voidElements } from "./voidElements.js";
 
-const { selfClosingElements, voidElements } = require("./voidElements");
-
-module.exports = {
- chunkToMarkup,
- opentag,
- closetag,
+export {
  voidElements,
  selfClosingElements,
 };
 
-function chunkToMarkup({ name, data, text }) {
+export function chunkToMarkup({ name, data, text }) {
  let markup = "";
  if (text) markup += text;
  else if (name && data) markup += opentag(name, data);
@@ -19,7 +14,7 @@ function chunkToMarkup({ name, data, text }) {
  return markup;
 }
 
-function opentag(tagname, attribs) {
+export function opentag(tagname, attribs) {
  if (selfClosingElements.includes(tagname)) {
  return `<${tagname}${attributesToString(attribs)}/>`;
  }
@@ -29,7 +24,7 @@ function opentag(tagname, attribs) {
  return `<${tagname}${attributesToString(attribs)}>`;
 }
 
-function closetag(tagname) {
+export function closetag(tagname) {
  if (selfClosingElements.includes(tagname) || voidElements.includes(tagname)) {
  return "";
  }