Merge pull request #12721 from Microsoft/stringify_shim

Remove JSON.stringify shim

Author: Andy

src/compiler/core.ts

@@ -863,24 +863,6 @@ namespace ts {
         return result;
     }
 
-    /**
-     * Reduce the properties defined on a map-like (but not from its prototype chain).
-     *
-     * NOTE: This is intended for use with MapLike<T> objects. For Map<T> objects, use
-     *       reduceProperties instead as it offers better performance.
-     *
-     * @param map The map-like to reduce
-     * @param callback An aggregation function that is called for each entry in the map
-     * @param initial The initial value for the reduction.
-     */
-    export function reduceOwnProperties<T, U>(map: MapLike<T>, callback: (aggregate: U, value: T, key: string) => U, initial: U): U {
-        let result = initial;
-        for (const key in map) if (hasOwnProperty.call(map, key)) {
-            result = callback(result, map[key], String(key));
-        }
-        return result;
-    }
-
     /**
      * Performs a shallow equality comparison of the contents of two map-likes.
      *

src/compiler/sourcemap.ts

@@ -427,7 +427,7 @@ namespace ts {
 
             encodeLastRecordedSourceMapSpan();
 
-            return stringify({
+            return JSON.stringify({
                 version: 3,
                 file: sourceMapData.sourceMapFile,
                 sourceRoot: sourceMapData.sourceMapSourceRoot,

src/compiler/utilities.ts

@@ -3189,55 +3189,6 @@ namespace ts {
         return output;
     }
 
-    /**
-     * Serialize an object graph into a JSON string. This is intended only for use on an acyclic graph
-     * as the fallback implementation does not check for circular references by default.
-     */
-    export const stringify: (value: any) => string = typeof JSON !== "undefined" && JSON.stringify
-        ? JSON.stringify
-        : stringifyFallback;
-
-    /**
-     * Serialize an object graph into a JSON string.
-     */
-    function stringifyFallback(value: any): string {
-        // JSON.stringify returns `undefined` here, instead of the string "undefined".
-        return value === undefined ? undefined : stringifyValue(value);
-    }
-
-    function stringifyValue(value: any): string {
-        return typeof value === "string" ? `"${escapeString(value)}"`
-            : typeof value === "number" ? isFinite(value) ? String(value) : "null"
-                : typeof value === "boolean" ? value ? "true" : "false"
-                    : typeof value === "object" && value ? isArray(value) ? cycleCheck(stringifyArray, value) : cycleCheck(stringifyObject, value)
-                        : /*fallback*/ "null";
-    }
-
-    function cycleCheck(cb: (value: any) => string, value: any) {
-        Debug.assert(!value.hasOwnProperty("__cycle"), "Converting circular structure to JSON");
-        value.__cycle = true;
-        const result = cb(value);
-        delete value.__cycle;
-        return result;
-    }
-
-    function stringifyArray(value: any) {
-        return `[${reduceLeft(value, stringifyElement, "")}]`;
-    }
-
-    function stringifyElement(memo: string, value: any) {
-        return (memo ? memo + "," : memo) + stringifyValue(value);
-    }
-
-    function stringifyObject(value: any) {
-        return `{${reduceOwnProperties(value, stringifyProperty, "")}}`;
-    }
-
-    function stringifyProperty(memo: string, value: any, key: string) {
-        return value === undefined || typeof value === "function" || key === "__cycle" ? memo
-            : (memo ? memo + "," : memo) + `"${escapeString(key)}":${stringifyValue(value)}`;
-    }
-
     const base64Digits = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
 
     /**