Add JSON5 support

DavidArchibald · Mar 21, 2021 · 642fbc6 · 642fbc6
1 parent 019397d
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diff --git a/README.md b/README.md
@@ -1,19 +1,13 @@
 
-JSON-ASTy
+JSON5-ASTy
 =========
 
-Lossless JSON-to-AST Parser and AST-to-JSON Generator
-
-<p/>
-<img src="https://nodei.co/npm/json-asty.png?downloads=true&stars=true" alt=""/>
-
-<p/>
-<img src="https://david-dm.org/rse/json-asty.png" alt=""/>
+Lossless JSON5-to-AST Parser and AST-to-JSON5 Generator forked from JSON-ASTy. The rest of the description is copied verbatim except to replace the name.
 
 About
 -----
 
-JSON-ASTy is a JavaScript library providing a lossless JavaScript Object
+JSON5-ASTy is a JavaScript library providing a lossless JavaScript Object
 Notation (JSON) to Abstract Syntax Tree (AST) parser and a corresponding
 AST to JSON generator. It is intended for cases where one has to read
 JSON into an AST, manipulate the AST and generate JSON from the AST
@@ -26,14 +20,14 @@ Installation
 ------------
 
 ```shell
-$ npm install json-asty
+$ npm install json5-asty
 ```
 
 Usage
 -----
 
 ```js
-const JsonAsty = require("json-asty")
+const JsonAsty = require("json5-asty")
 
 /*  the JSON input  */
 let json = `{
@@ -157,4 +151,3 @@ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
diff --git a/package.json b/package.json
@@ -14,9 +14,16 @@
         "email": "[email protected]",
         "url":   "http://engelschall.com"
     },
+    "contributors": [
+        {
+            "name": "LukeAbby",
+            "email": "[email protected]",
+            "url": "http://gitlab.com/LukeAbby/"
+        }
+    ],
     "license":  "MIT",
-    "homepage": "https://github.com/rse/json-asty",
-    "bugs":     "https://github.com/rse/json-asty/issues",
+    "homepage": "https://github.com/DavidArchibald/json5-asty",
+    "bugs":     "https://github.com/DavidArchibald/json5-astyissues",
     "dependencies": {
         "asty-astq":                                 "1.13.4",
         "pegjs-otf":                                 "1.2.18",

diff --git a/src/json-asty.d.ts b/src/json-asty.d.ts
@@ -1,38 +1,37 @@
 /*!
-**  JSON-ASTy -- Lossless JSON-to-AST Parser and AST-to-JSON Generator
-**  Copyright (c) 2018-2021 Dr. Ralf S. Engelschall <[email protected]>
-**
-**  Permission is hereby granted, free of charge, to any person obtaining
-**  a copy of this software and associated documentation files (the
-**  "Software"), to deal in the Software without restriction, including
-**  without limitation the rights to use, copy, modify, merge, publish,
-**  distribute, sublicense, and/or sell copies of the Software, and to
-**  permit persons to whom the Software is furnished to do so, subject to
-**  the following conditions:
-**
-**  The above copyright notice and this permission notice shall be included
-**  in all copies or substantial portions of the Software.
-**
-**  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-**  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-**  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
-**  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
-**  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
-**  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
-**  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-*/
+ **  JSON-ASTy -- Lossless JSON-to-AST Parser and AST-to-JSON Generator
+ **  Copyright (c) 2018-2021 Dr. Ralf S. Engelschall <[email protected]>
+ **
+ **  Permission is hereby granted, free of charge, to any person obtaining
+ **  a copy of this software and associated documentation files (the
+ **  "Software"), to deal in the Software without restriction, including
+ **  without limitation the rights to use, copy, modify, merge, publish,
+ **  distribute, sublicense, and/or sell copies of the Software, and to
+ **  permit persons to whom the Software is furnished to do so, subject to
+ **  the following conditions:
+ **
+ **  The above copyright notice and this permission notice shall be included
+ **  in all copies or substantial portions of the Software.
+ **
+ **  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ **  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ **  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ **  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ **  CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ **  TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ **  SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
 
-declare module "JsonAsty" {
-    class JsonAsty {
-        /*  parse JSON into AST  */
-        static parse(json: string): object;
+declare module 'JsonAsty' {
+	class JsonAsty {
+		/*  parse JSON into AST  */
+		static parse(json: string): object;
 
-        /*  dump AST  */
-        static dump(ast: object, options?: { colors?: boolean }): string;
+		/*  dump AST  */
+		static dump(ast: object, options?: { colors?: boolean }): string;
 
-        /*  unparse AST into JSON  */
-        static unparse(ast: object): string;
-    }
-    export = JsonAsty
+		/*  unparse AST into JSON  */
+		static unparse(ast: object): string;
+	}
+	export = JsonAsty;
 }
-
diff --git a/src/json-asty.js b/src/json-asty.js
@@ -23,97 +23,116 @@
 */
 
 /*  external requirements  */
-const ASTY        = require("asty-astq")
-const PEG         = require("pegjs-otf")
-const PEGUtil     = require("pegjs-util")
-const chalk       = require("chalk")
+const ASTY = require("asty-astq");
+const PEG = require("pegjs-otf");
+const PEGUtil = require("pegjs-util");
+const chalk = require("chalk");
 
 /*  pre-parse PEG grammar (replaced by browserify)  */
-const PEGparser = PEG.generateFromFile(`${__dirname}/json-asty.pegjs`, {
-    optimize: "size",
-    trace: false
-})
+const jsonParser = PEG.generateFromFile(`${__dirname}/json-asty.pegjs`, {
+  optimize: "size",
+  trace: false,
+});
+
+const json5Parser = PEG.generateFromFile(`${__dirname}/json5-asty.pegjs`, {
+  optimize: "size",
+  trace: false,
+});
 
 /*  the API class  */
 class JsonAsty {
-    /*  parse JSON into AST  */
-    static parse (json) {
-        /*  sanity check argument  */
-        if (typeof json !== "string")
-            throw new Error("invalid JSON argument (expected type string)")
+  /*  parse JSON into AST  */
+  static parse(json, json5=true) {
+    /*  sanity check argument  */
+    if (typeof json !== "string")
+      throw new Error("invalid JSON argument (expected type string)");
 
-        /*  parse specification into Abstract Syntax Tree (AST)  */
-        const asty = new ASTY()
-        const result = PEGUtil.parse(PEGparser, json, {
-            startRule: "json",
-            makeAST: (line, column, offset, args) => {
-                return asty.create.apply(asty, args).pos(line, column, offset)
-            }
-        })
-        if (result.error !== null)
-            throw new Error("parse: JSON parsing failure:\n" +
-                PEGUtil.errorMessage(result.error, true).replace(/^/mg, "ERROR: ") + "\n")
-        return result.ast
+    let parser;
+    if (json5) {
+      parser = json5Parser;
+    } else {
+      parser = jsonParser;
     }
 
-    /*  dump AST (with optional colorization)  */
-    static dump (ast, options = {}) {
-        /*  determine options  */
-        options = Object.assign({}, {
-            colors: false
-        }, options)
+    /*  parse specification into Abstract Syntax Tree (AST)  */
+    const asty = new ASTY();
+    const result = PEGUtil.parse(parser, json, {
+      startRule: "json",
+      makeAST: (line, column, offset, args) => {
+        return asty.create.apply(asty, args).pos(line, column, offset);
+      },
+    });
+    if (result.error !== null)
+      throw new Error(
+        "parse: JSON parsing failure:\n" +
+          PEGUtil.errorMessage(result.error, true).replace(/^/gm, "ERROR: ") +
+          "\n",
+      );
+    return result.ast;
+  }
+
+  /*  dump AST (with optional colorization)  */
+  static dump(ast, options = {}) {
+    /*  determine options  */
+    options = Object.assign(
+      {},
+      {
+        colors: false,
+      },
+      options,
+    );
 
-        /* eslint no-console: off */
-        let output
-        if (options.colors) {
-            output = ast.dump(Infinity, (type, text) => {
-                switch (type) {
-                    case "tree":     text = chalk.grey(text);   break
-                    case "type":     text = chalk.blue(text);   break
-                    case "value":    text = chalk.yellow(text); break
-                    case "position": text = chalk.grey(text);   break
-                    default:
-                }
-                return text
-            })
+    /* eslint no-console: off */
+    let output;
+    if (options.colors) {
+      output = ast.dump(Infinity, (type, text) => {
+        switch (type) {
+          case "tree":
+            text = chalk.grey(text);
+            break;
+          case "type":
+            text = chalk.blue(text);
+            break;
+          case "value":
+            text = chalk.yellow(text);
+            break;
+          case "position":
+            text = chalk.grey(text);
+            break;
+          default:
         }
-        else
-            output = ast.dump(Infinity)
-        return output
-    }
+        return text;
+      });
+    } else output = ast.dump(Infinity);
+    return output;
+  }
 
-    /*  unparse AST into JSON  */
-    static unparse (ast) {
-        /*  sanity check arguments  */
-        if (typeof ast !== "object")
-            throw new Error("generate: invalid AST argument (expected type object)")
+  /*  unparse AST into JSON  */
+  static unparse(ast) {
+    /*  sanity check arguments  */
+    if (typeof ast !== "object")
+      throw new Error("generate: invalid AST argument (expected type object)");
 
-        /*  walk the AST  */
-        let json = ""
-        ast.walk((node, depth, parent, when) => {
-            if (when === "downward") {
-                const prolog = node.get("prolog")
-                if (prolog !== undefined)
-                    json += prolog
-                const body = node.get("body")
-                if (body !== undefined)
-                    json += body
-                else {
-                    const value = node.get("value")
-                    if (value !== undefined)
-                        json += JSON.stringify(value)
-                }
-            }
-            else if (when === "upward") {
-                const epilog = node.get("epilog")
-                if (epilog !== undefined)
-                    json += epilog
-            }
-        }, "both")
-        return json
-    }
+    /*  walk the AST  */
+    let json = "";
+    ast.walk((node, depth, parent, when) => {
+      if (when === "downward") {
+        const prolog = node.get("prolog");
+        if (prolog !== undefined) json += prolog;
+        const body = node.get("body");
+        if (body !== undefined) json += body;
+        else {
+          const value = node.get("value");
+          if (value !== undefined) json += JSON.stringify(value);
+        }
+      } else if (when === "upward") {
+        const epilog = node.get("epilog");
+        if (epilog !== undefined) json += epilog;
+      }
+    }, "both");
+    return json;
+  }
 }
 
 /*  export the API class  */
-module.exports = JsonAsty
-
+module.exports = JsonAsty;
diff --git a/src/json-asty.pegjs b/src/json-asty.pegjs
@@ -124,6 +124,9 @@ valueString "quoted string literal value"
             }
         )*
         '"' {
+            if (text() === "" || text() == null) {
+              return ast("string").set({ body: '""', value: ""})
+            }
             return ast("string").set({ body: text(), value: chars.join("") })
         }
 
@@ -147,4 +150,3 @@ ws "whitespace"
 
 eof "end of file"
     =   !.
-