Fix StringUtils.ensureQuoted to escape multiple quotations (#382)

package-lock.json

@@ -1,12 +1,12 @@
 {
     "name": "@microsoft/powerquery-parser",
-    "version": "0.15.8",
+    "version": "0.15.10",
     "lockfileVersion": 2,
     "requires": true,
     "packages": {
         "": {
             "name": "@microsoft/powerquery-parser",
-            "version": "0.15.8",
+            "version": "0.15.10",
             "license": "MIT",
             "dependencies": {
                 "grapheme-splitter": "^1.0.4",

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@microsoft/powerquery-parser",
-    "version": "0.15.9",
+    "version": "0.15.10",
     "description": "A parser for the Power Query/M formula language.",
     "author": "Microsoft",
     "license": "MIT",

src/powerquery-parser/common/stringUtils.ts

@@ -45,7 +45,7 @@ export function ensureQuoted(text: string): string {
         return text;
     }
 
-    return `"${text.includes(`"`) ? text.replace(`"`, `""`) : text}"`;
+    return `"${text.replace(/"/g, '""')}"`;
 }
 
 export function columnNumberFrom(text: string, requiredCodeUnit: number): number {

src/test/libraryTest/common/stringUtils.ts

@@ -13,6 +13,7 @@ describe("StringUtils", () => {
         it(`"`, () => expect(StringUtils.ensureQuoted(`"`)).to.equal(`""""`));
         it(`""`, () => expect(StringUtils.ensureQuoted(`""`)).to.equal(`""`));
         it(`"a"`, () => expect(StringUtils.ensureQuoted(`"a"`)).to.equal(`"a"`));
+        it(`a"b"c`, () => expect(StringUtils.ensureQuoted(`a"b"c`)).to.equal(`"a""b""c"`));
     });
 
     describe(`findQuote`, () => {