From c219fdae08607e07ec875d2137fcba7c2d93792c Mon Sep 17 00:00:00 2001
From: Alexander T <alexander.tarasyuk@outlook.com>
Date: Tue, 5 May 2020 20:29:17 +0300
Subject: [PATCH] fix(37703): forbid required parameter after optional (#38155)

---
 src/compiler/checker.ts                       |  5 ++---
 .../checkJsdocOptionalParamOrder.errors.txt   | 14 +++++++++++++
 .../reference/checkJsdocOptionalParamOrder.js | 18 +++++++++++++++++
 .../checkJsdocOptionalParamOrder.symbols      | 13 ++++++++++++
 .../checkJsdocOptionalParamOrder.types        | 13 ++++++++++++
 .../jsdocParseBackquotedParamName.errors.txt  | 20 +++++++++++++++++++
 .../jsdoc/checkJsdocOptionalParamOrder.ts     | 11 ++++++++++
 7 files changed, 91 insertions(+), 3 deletions(-)
 create mode 100644 tests/baselines/reference/checkJsdocOptionalParamOrder.errors.txt
 create mode 100644 tests/baselines/reference/checkJsdocOptionalParamOrder.js
 create mode 100644 tests/baselines/reference/checkJsdocOptionalParamOrder.symbols
 create mode 100644 tests/baselines/reference/checkJsdocOptionalParamOrder.types
 create mode 100644 tests/baselines/reference/jsdocParseBackquotedParamName.errors.txt
 create mode 100644 tests/cases/conformance/jsdoc/checkJsdocOptionalParamOrder.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index c9287634789..7a70426aae8 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -37048,10 +37048,9 @@ namespace ts {
                         return grammarErrorOnNode(parameter.name, Diagnostics.A_rest_parameter_cannot_have_an_initializer);
                     }
                 }
-                else if (parameter.questionToken) {
+                else if (isOptionalParameter(parameter)) {
                     seenOptionalParameter = true;
-
-                    if (parameter.initializer) {
+                    if (parameter.questionToken && parameter.initializer) {
                         return grammarErrorOnNode(parameter.name, Diagnostics.Parameter_cannot_have_question_mark_and_initializer);
                     }
                 }
diff --git a/tests/baselines/reference/checkJsdocOptionalParamOrder.errors.txt b/tests/baselines/reference/checkJsdocOptionalParamOrder.errors.txt
new file mode 100644
index 00000000000..82e6f5c5d15
--- /dev/null
+++ b/tests/baselines/reference/checkJsdocOptionalParamOrder.errors.txt
@@ -0,0 +1,14 @@
+tests/cases/conformance/jsdoc/0.js(7,20): error TS1016: A required parameter cannot follow an optional parameter.
+
+
+==== tests/cases/conformance/jsdoc/0.js (1 errors) ====
+    // @ts-check
+    /**
+     * @param {number} a
+     * @param {number} [b]
+     * @param {number} c
+     */
+    function foo(a, b, c) {}
+                       ~
+!!! error TS1016: A required parameter cannot follow an optional parameter.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/checkJsdocOptionalParamOrder.js b/tests/baselines/reference/checkJsdocOptionalParamOrder.js
new file mode 100644
index 00000000000..69b999fb2bd
--- /dev/null
+++ b/tests/baselines/reference/checkJsdocOptionalParamOrder.js
@@ -0,0 +1,18 @@
+//// [0.js]
+// @ts-check
+/**
+ * @param {number} a
+ * @param {number} [b]
+ * @param {number} c
+ */
+function foo(a, b, c) {}
+
+
+//// [0.js]
+// @ts-check
+/**
+ * @param {number} a
+ * @param {number} [b]
+ * @param {number} c
+ */
+function foo(a, b, c) { }
diff --git a/tests/baselines/reference/checkJsdocOptionalParamOrder.symbols b/tests/baselines/reference/checkJsdocOptionalParamOrder.symbols
new file mode 100644
index 00000000000..786f7a1bcf5
--- /dev/null
+++ b/tests/baselines/reference/checkJsdocOptionalParamOrder.symbols
@@ -0,0 +1,13 @@
+=== tests/cases/conformance/jsdoc/0.js ===
+// @ts-check
+/**
+ * @param {number} a
+ * @param {number} [b]
+ * @param {number} c
+ */
+function foo(a, b, c) {}
+>foo : Symbol(foo, Decl(0.js, 0, 0))
+>a : Symbol(a, Decl(0.js, 6, 13))
+>b : Symbol(b, Decl(0.js, 6, 15))
+>c : Symbol(c, Decl(0.js, 6, 18))
+
diff --git a/tests/baselines/reference/checkJsdocOptionalParamOrder.types b/tests/baselines/reference/checkJsdocOptionalParamOrder.types
new file mode 100644
index 00000000000..1636462c8a9
--- /dev/null
+++ b/tests/baselines/reference/checkJsdocOptionalParamOrder.types
@@ -0,0 +1,13 @@
+=== tests/cases/conformance/jsdoc/0.js ===
+// @ts-check
+/**
+ * @param {number} a
+ * @param {number} [b]
+ * @param {number} c
+ */
+function foo(a, b, c) {}
+>foo : (a: number, b?: number, c: number) => void
+>a : number
+>b : number
+>c : number
+
diff --git a/tests/baselines/reference/jsdocParseBackquotedParamName.errors.txt b/tests/baselines/reference/jsdocParseBackquotedParamName.errors.txt
new file mode 100644
index 00000000000..60ba155b1f9
--- /dev/null
+++ b/tests/baselines/reference/jsdocParseBackquotedParamName.errors.txt
@@ -0,0 +1,20 @@
+tests/cases/conformance/jsdoc/a.js(5,18): error TS1016: A required parameter cannot follow an optional parameter.
+
+
+==== tests/cases/conformance/jsdoc/a.js (1 errors) ====
+    /**
+     * @param {string=} `args`
+     * @param `bwarg` {?number?}
+     */
+    function f(args, bwarg) {
+                     ~~~~~
+!!! error TS1016: A required parameter cannot follow an optional parameter.
+    }
+    
+==== tests/cases/conformance/jsdoc/ts.ts (0 errors) ====
+    /**
+     * @param `arg` - this is fine
+     */
+    function g(arg: string) {
+    }
+    
\ No newline at end of file
diff --git a/tests/cases/conformance/jsdoc/checkJsdocOptionalParamOrder.ts b/tests/cases/conformance/jsdoc/checkJsdocOptionalParamOrder.ts
new file mode 100644
index 00000000000..c498720c133
--- /dev/null
+++ b/tests/cases/conformance/jsdoc/checkJsdocOptionalParamOrder.ts
@@ -0,0 +1,11 @@
+// @allowJS: true
+// @suppressOutputPathCheck: true
+
+// @filename: 0.js
+// @ts-check
+/**
+ * @param {number} a
+ * @param {number} [b]
+ * @param {number} c
+ */
+function foo(a, b, c) {}