From cdf5b7aeb382be8ccc946a687be0c803c6ff89ab Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Tue, 7 Jun 2016 17:37:18 -0700
Subject: [PATCH] Add tests

---
 .../reference/typeGuardsNestedAssignments.js  |  86 ++++++++++
 .../typeGuardsNestedAssignments.symbols       | 113 +++++++++++++
 .../typeGuardsNestedAssignments.types         | 155 ++++++++++++++++++
 .../typeGuardsNestedAssignments.ts            |  47 ++++++
 4 files changed, 401 insertions(+)
 create mode 100644 tests/baselines/reference/typeGuardsNestedAssignments.js
 create mode 100644 tests/baselines/reference/typeGuardsNestedAssignments.symbols
 create mode 100644 tests/baselines/reference/typeGuardsNestedAssignments.types
 create mode 100644 tests/cases/conformance/controlFlow/typeGuardsNestedAssignments.ts

diff --git a/tests/baselines/reference/typeGuardsNestedAssignments.js b/tests/baselines/reference/typeGuardsNestedAssignments.js
new file mode 100644
index 00000000000..f37db041006
--- /dev/null
+++ b/tests/baselines/reference/typeGuardsNestedAssignments.js
@@ -0,0 +1,86 @@
+//// [typeGuardsNestedAssignments.ts]
+
+class Foo {
+    x: string;
+}
+
+declare function getFooOrNull(): Foo | null;
+declare function getStringOrNumberOrNull(): string | number | null;
+
+function f1() {
+    let foo: Foo | null;
+    if ((foo = getFooOrNull()) !== null) {
+        foo;  // Foo
+    }
+}
+
+function f2() {
+    let foo1: Foo | null;
+    let foo2: Foo | null;
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+        foo1;  // Foo | null
+        foo2;  // Foo
+    }
+}
+
+function f3() {
+    let obj: Object | null;
+    if ((obj = getFooOrNull()) instanceof Foo) {
+        obj;
+    }
+}
+
+function f4() {
+    let x: string | number | null;
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+        x;
+    }
+}
+
+// Repro from #8851
+
+const re = /./g
+let match: RegExpExecArray | null
+
+while ((match = re.exec("xxx")) != null) {
+    const length = match[1].length + match[2].length
+}
+
+//// [typeGuardsNestedAssignments.js]
+var Foo = (function () {
+    function Foo() {
+    }
+    return Foo;
+}());
+function f1() {
+    var foo;
+    if ((foo = getFooOrNull()) !== null) {
+        foo; // Foo
+    }
+}
+function f2() {
+    var foo1;
+    var foo2;
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+        foo1; // Foo | null
+        foo2; // Foo
+    }
+}
+function f3() {
+    var obj;
+    if ((obj = getFooOrNull()) instanceof Foo) {
+        obj;
+    }
+}
+function f4() {
+    var x;
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+        x;
+    }
+}
+// Repro from #8851
+var re = /./g;
+var match;
+while ((match = re.exec("xxx")) != null) {
+    var length = match[1].length + match[2].length;
+}
diff --git a/tests/baselines/reference/typeGuardsNestedAssignments.symbols b/tests/baselines/reference/typeGuardsNestedAssignments.symbols
new file mode 100644
index 00000000000..1cca9c7de73
--- /dev/null
+++ b/tests/baselines/reference/typeGuardsNestedAssignments.symbols
@@ -0,0 +1,113 @@
+=== tests/cases/conformance/controlFlow/typeGuardsNestedAssignments.ts ===
+
+class Foo {
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+    x: string;
+>x : Symbol(Foo.x, Decl(typeGuardsNestedAssignments.ts, 1, 11))
+}
+
+declare function getFooOrNull(): Foo | null;
+>getFooOrNull : Symbol(getFooOrNull, Decl(typeGuardsNestedAssignments.ts, 3, 1))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+declare function getStringOrNumberOrNull(): string | number | null;
+>getStringOrNumberOrNull : Symbol(getStringOrNumberOrNull, Decl(typeGuardsNestedAssignments.ts, 5, 44))
+
+function f1() {
+>f1 : Symbol(f1, Decl(typeGuardsNestedAssignments.ts, 6, 67))
+
+    let foo: Foo | null;
+>foo : Symbol(foo, Decl(typeGuardsNestedAssignments.ts, 9, 7))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+    if ((foo = getFooOrNull()) !== null) {
+>foo : Symbol(foo, Decl(typeGuardsNestedAssignments.ts, 9, 7))
+>getFooOrNull : Symbol(getFooOrNull, Decl(typeGuardsNestedAssignments.ts, 3, 1))
+
+        foo;  // Foo
+>foo : Symbol(foo, Decl(typeGuardsNestedAssignments.ts, 9, 7))
+    }
+}
+
+function f2() {
+>f2 : Symbol(f2, Decl(typeGuardsNestedAssignments.ts, 13, 1))
+
+    let foo1: Foo | null;
+>foo1 : Symbol(foo1, Decl(typeGuardsNestedAssignments.ts, 16, 7))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+    let foo2: Foo | null;
+>foo2 : Symbol(foo2, Decl(typeGuardsNestedAssignments.ts, 17, 7))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+>foo1 : Symbol(foo1, Decl(typeGuardsNestedAssignments.ts, 16, 7))
+>getFooOrNull : Symbol(getFooOrNull, Decl(typeGuardsNestedAssignments.ts, 3, 1))
+>foo2 : Symbol(foo2, Decl(typeGuardsNestedAssignments.ts, 17, 7))
+>foo1 : Symbol(foo1, Decl(typeGuardsNestedAssignments.ts, 16, 7))
+
+        foo1;  // Foo | null
+>foo1 : Symbol(foo1, Decl(typeGuardsNestedAssignments.ts, 16, 7))
+
+        foo2;  // Foo
+>foo2 : Symbol(foo2, Decl(typeGuardsNestedAssignments.ts, 17, 7))
+    }
+}
+
+function f3() {
+>f3 : Symbol(f3, Decl(typeGuardsNestedAssignments.ts, 22, 1))
+
+    let obj: Object | null;
+>obj : Symbol(obj, Decl(typeGuardsNestedAssignments.ts, 25, 7))
+>Object : Symbol(Object, Decl(lib.d.ts, --, --), Decl(lib.d.ts, --, --))
+
+    if ((obj = getFooOrNull()) instanceof Foo) {
+>obj : Symbol(obj, Decl(typeGuardsNestedAssignments.ts, 25, 7))
+>getFooOrNull : Symbol(getFooOrNull, Decl(typeGuardsNestedAssignments.ts, 3, 1))
+>Foo : Symbol(Foo, Decl(typeGuardsNestedAssignments.ts, 0, 0))
+
+        obj;
+>obj : Symbol(obj, Decl(typeGuardsNestedAssignments.ts, 25, 7))
+    }
+}
+
+function f4() {
+>f4 : Symbol(f4, Decl(typeGuardsNestedAssignments.ts, 29, 1))
+
+    let x: string | number | null;
+>x : Symbol(x, Decl(typeGuardsNestedAssignments.ts, 32, 7))
+
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+>x : Symbol(x, Decl(typeGuardsNestedAssignments.ts, 32, 7))
+>getStringOrNumberOrNull : Symbol(getStringOrNumberOrNull, Decl(typeGuardsNestedAssignments.ts, 5, 44))
+
+        x;
+>x : Symbol(x, Decl(typeGuardsNestedAssignments.ts, 32, 7))
+    }
+}
+
+// Repro from #8851
+
+const re = /./g
+>re : Symbol(re, Decl(typeGuardsNestedAssignments.ts, 40, 5))
+
+let match: RegExpExecArray | null
+>match : Symbol(match, Decl(typeGuardsNestedAssignments.ts, 41, 3))
+>RegExpExecArray : Symbol(RegExpExecArray, Decl(lib.d.ts, --, --))
+
+while ((match = re.exec("xxx")) != null) {
+>match : Symbol(match, Decl(typeGuardsNestedAssignments.ts, 41, 3))
+>re.exec : Symbol(RegExp.exec, Decl(lib.d.ts, --, --))
+>re : Symbol(re, Decl(typeGuardsNestedAssignments.ts, 40, 5))
+>exec : Symbol(RegExp.exec, Decl(lib.d.ts, --, --))
+
+    const length = match[1].length + match[2].length
+>length : Symbol(length, Decl(typeGuardsNestedAssignments.ts, 44, 9))
+>match[1].length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>match : Symbol(match, Decl(typeGuardsNestedAssignments.ts, 41, 3))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>match[2].length : Symbol(String.length, Decl(lib.d.ts, --, --))
+>match : Symbol(match, Decl(typeGuardsNestedAssignments.ts, 41, 3))
+>length : Symbol(String.length, Decl(lib.d.ts, --, --))
+}
diff --git a/tests/baselines/reference/typeGuardsNestedAssignments.types b/tests/baselines/reference/typeGuardsNestedAssignments.types
new file mode 100644
index 00000000000..566a39a9c23
--- /dev/null
+++ b/tests/baselines/reference/typeGuardsNestedAssignments.types
@@ -0,0 +1,155 @@
+=== tests/cases/conformance/controlFlow/typeGuardsNestedAssignments.ts ===
+
+class Foo {
+>Foo : Foo
+
+    x: string;
+>x : string
+}
+
+declare function getFooOrNull(): Foo | null;
+>getFooOrNull : () => Foo | null
+>Foo : Foo
+>null : null
+
+declare function getStringOrNumberOrNull(): string | number | null;
+>getStringOrNumberOrNull : () => string | number | null
+>null : null
+
+function f1() {
+>f1 : () => void
+
+    let foo: Foo | null;
+>foo : Foo | null
+>Foo : Foo
+>null : null
+
+    if ((foo = getFooOrNull()) !== null) {
+>(foo = getFooOrNull()) !== null : boolean
+>(foo = getFooOrNull()) : Foo | null
+>foo = getFooOrNull() : Foo | null
+>foo : Foo | null
+>getFooOrNull() : Foo | null
+>getFooOrNull : () => Foo | null
+>null : null
+
+        foo;  // Foo
+>foo : Foo
+    }
+}
+
+function f2() {
+>f2 : () => void
+
+    let foo1: Foo | null;
+>foo1 : Foo | null
+>Foo : Foo
+>null : null
+
+    let foo2: Foo | null;
+>foo2 : Foo | null
+>Foo : Foo
+>null : null
+
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+>(foo1 = getFooOrNull(), foo2 = foo1) !== null : boolean
+>(foo1 = getFooOrNull(), foo2 = foo1) : Foo | null
+>foo1 = getFooOrNull(), foo2 = foo1 : Foo | null
+>foo1 = getFooOrNull() : Foo | null
+>foo1 : Foo | null
+>getFooOrNull() : Foo | null
+>getFooOrNull : () => Foo | null
+>foo2 = foo1 : Foo | null
+>foo2 : Foo | null
+>foo1 : Foo | null
+>null : null
+
+        foo1;  // Foo | null
+>foo1 : Foo | null
+
+        foo2;  // Foo
+>foo2 : Foo
+    }
+}
+
+function f3() {
+>f3 : () => void
+
+    let obj: Object | null;
+>obj : Object | null
+>Object : Object
+>null : null
+
+    if ((obj = getFooOrNull()) instanceof Foo) {
+>(obj = getFooOrNull()) instanceof Foo : boolean
+>(obj = getFooOrNull()) : Foo | null
+>obj = getFooOrNull() : Foo | null
+>obj : Object | null
+>getFooOrNull() : Foo | null
+>getFooOrNull : () => Foo | null
+>Foo : typeof Foo
+
+        obj;
+>obj : Foo
+    }
+}
+
+function f4() {
+>f4 : () => void
+
+    let x: string | number | null;
+>x : string | number | null
+>null : null
+
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+>typeof (x = getStringOrNumberOrNull()) === "number" : boolean
+>typeof (x = getStringOrNumberOrNull()) : string
+>(x = getStringOrNumberOrNull()) : string | number | null
+>x = getStringOrNumberOrNull() : string | number | null
+>x : string | number | null
+>getStringOrNumberOrNull() : string | number | null
+>getStringOrNumberOrNull : () => string | number | null
+>"number" : string
+
+        x;
+>x : number
+    }
+}
+
+// Repro from #8851
+
+const re = /./g
+>re : RegExp
+>/./g : RegExp
+
+let match: RegExpExecArray | null
+>match : RegExpExecArray | null
+>RegExpExecArray : RegExpExecArray
+>null : null
+
+while ((match = re.exec("xxx")) != null) {
+>(match = re.exec("xxx")) != null : boolean
+>(match = re.exec("xxx")) : RegExpExecArray | null
+>match = re.exec("xxx") : RegExpExecArray | null
+>match : RegExpExecArray | null
+>re.exec("xxx") : RegExpExecArray | null
+>re.exec : (string: string) => RegExpExecArray | null
+>re : RegExp
+>exec : (string: string) => RegExpExecArray | null
+>"xxx" : string
+>null : null
+
+    const length = match[1].length + match[2].length
+>length : number
+>match[1].length + match[2].length : number
+>match[1].length : number
+>match[1] : string
+>match : RegExpExecArray
+>1 : number
+>length : number
+>match[2].length : number
+>match[2] : string
+>match : RegExpExecArray
+>2 : number
+>length : number
+}
diff --git a/tests/cases/conformance/controlFlow/typeGuardsNestedAssignments.ts b/tests/cases/conformance/controlFlow/typeGuardsNestedAssignments.ts
new file mode 100644
index 00000000000..41e3ffe572e
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/typeGuardsNestedAssignments.ts
@@ -0,0 +1,47 @@
+// @strictNullChecks: true
+
+class Foo {
+    x: string;
+}
+
+declare function getFooOrNull(): Foo | null;
+declare function getStringOrNumberOrNull(): string | number | null;
+
+function f1() {
+    let foo: Foo | null;
+    if ((foo = getFooOrNull()) !== null) {
+        foo;  // Foo
+    }
+}
+
+function f2() {
+    let foo1: Foo | null;
+    let foo2: Foo | null;
+    if ((foo1 = getFooOrNull(), foo2 = foo1) !== null) {
+        foo1;  // Foo | null
+        foo2;  // Foo
+    }
+}
+
+function f3() {
+    let obj: Object | null;
+    if ((obj = getFooOrNull()) instanceof Foo) {
+        obj;
+    }
+}
+
+function f4() {
+    let x: string | number | null;
+    if (typeof (x = getStringOrNumberOrNull()) === "number") {
+        x;
+    }
+}
+
+// Repro from #8851
+
+const re = /./g
+let match: RegExpExecArray | null
+
+while ((match = re.exec("xxx")) != null) {
+    const length = match[1].length + match[2].length
+}
\ No newline at end of file