Fix missing tokenToString for the backtick token

src/compiler/scanner.ts

@@ -197,6 +197,7 @@ namespace ts {
         "|=": SyntaxKind.BarEqualsToken,
         "^=": SyntaxKind.CaretEqualsToken,
         "@": SyntaxKind.AtToken,
+        "`": SyntaxKind.BacktickToken
     });
 
     /*
@@ -298,7 +299,6 @@ namespace ts {
     }
 
     const tokenStrings = makeReverseMap(textToToken);
-
     export function tokenToString(t: SyntaxKind): string | undefined {
         return tokenStrings[t];
     }

src/testRunner/unittests/publicApi.ts

@@ -31,3 +31,18 @@ describe("Public APIs", () => {
         verifyApi("tsserverlibrary.d.ts");
     });
 });
+
+describe("Public APIs:: token to string", () => {
+    function assertDefinedTokenToString(initial: ts.SyntaxKind, last: ts.SyntaxKind) {
+        for (let t = initial; t <= last; t++) {
+            assert.isDefined(ts.tokenToString(t), `Expected tokenToString defined for ${ts.Debug.formatSyntaxKind(t)}`);
+        }
+    }
+
+    it("for punctuations", () => {
+        assertDefinedTokenToString(ts.SyntaxKind.FirstPunctuation, ts.SyntaxKind.LastPunctuation);
+    });
+    it("for keywords", () => {
+        assertDefinedTokenToString(ts.SyntaxKind.FirstKeyword, ts.SyntaxKind.LastKeyword);
+    });
+});

tests/baselines/reference/jsdocParameterParsingInvalidName.js

@@ -0,0 +1,20 @@
+//// [jsdocParameterParsingInvalidName.ts]
+class c {
+    /**
+     * @param {string} [`foo]
+     */
+    method(foo) {
+    }
+}
+
+//// [jsdocParameterParsingInvalidName.js]
+var c = /** @class */ (function () {
+    function c() {
+    }
+    /**
+     * @param {string} [`foo]
+     */
+    c.prototype.method = function (foo) {
+    };
+    return c;
+}());

tests/baselines/reference/jsdocParameterParsingInvalidName.symbols

@@ -0,0 +1,12 @@
+=== tests/cases/compiler/jsdocParameterParsingInvalidName.ts ===
+class c {
+>c : Symbol(c, Decl(jsdocParameterParsingInvalidName.ts, 0, 0))
+
+    /**
+     * @param {string} [`foo]
+     */
+    method(foo) {
+>method : Symbol(c.method, Decl(jsdocParameterParsingInvalidName.ts, 0, 9))
+>foo : Symbol(foo, Decl(jsdocParameterParsingInvalidName.ts, 4, 11))
+    }
+}

tests/baselines/reference/jsdocParameterParsingInvalidName.types

@@ -0,0 +1,12 @@
+=== tests/cases/compiler/jsdocParameterParsingInvalidName.ts ===
+class c {
+>c : c
+
+    /**
+     * @param {string} [`foo]
+     */
+    method(foo) {
+>method : (foo: any) => void
+>foo : any
+    }
+}

tests/cases/compiler/jsdocParameterParsingInvalidName.ts

@@ -0,0 +1,7 @@
+class c {
+    /**
+     * @param {string} [`foo]
+     */
+    method(foo) {
+    }
+}