From 29ae2b2cf153ef7d28a50053c85e637ea2d02915 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Thu, 11 Aug 2016 14:38:17 -0700
Subject: [PATCH] Add regression tests

---
 .../reference/discriminantsAndPrimitives.js   |  84 +++++++++++
 .../discriminantsAndPrimitives.symbols        | 117 +++++++++++++++
 .../discriminantsAndPrimitives.types          | 141 ++++++++++++++++++
 .../compiler/discriminantsAndPrimitives.ts    |  49 ++++++
 4 files changed, 391 insertions(+)
 create mode 100644 tests/baselines/reference/discriminantsAndPrimitives.js
 create mode 100644 tests/baselines/reference/discriminantsAndPrimitives.symbols
 create mode 100644 tests/baselines/reference/discriminantsAndPrimitives.types
 create mode 100644 tests/cases/compiler/discriminantsAndPrimitives.ts

diff --git a/tests/baselines/reference/discriminantsAndPrimitives.js b/tests/baselines/reference/discriminantsAndPrimitives.js
new file mode 100644
index 00000000000..1d11781a707
--- /dev/null
+++ b/tests/baselines/reference/discriminantsAndPrimitives.js
@@ -0,0 +1,84 @@
+//// [discriminantsAndPrimitives.ts]
+
+// Repro from #10257 plus other tests
+
+interface Foo {
+    kind: "foo";
+    name: string;
+}
+
+interface Bar {
+    kind: "bar";
+    length: string;
+}
+
+function f1(x: Foo | Bar | string) {
+    if (typeof x !== 'string') {
+        switch(x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+
+function f2(x: Foo | Bar | string | undefined) {
+    if (typeof x === "object") {
+        switch(x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+
+function f3(x: Foo | Bar | string | null) {
+    if (x && typeof x !== "string") {
+        switch(x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+
+function f4(x: Foo | Bar | string | number | null) {
+    if (x && typeof x === "object") {
+        switch(x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+
+//// [discriminantsAndPrimitives.js]
+// Repro from #10257 plus other tests
+function f1(x) {
+    if (typeof x !== 'string') {
+        switch (x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+function f2(x) {
+    if (typeof x === "object") {
+        switch (x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+function f3(x) {
+    if (x && typeof x !== "string") {
+        switch (x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+function f4(x) {
+    if (x && typeof x === "object") {
+        switch (x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
diff --git a/tests/baselines/reference/discriminantsAndPrimitives.symbols b/tests/baselines/reference/discriminantsAndPrimitives.symbols
new file mode 100644
index 00000000000..c84f32cd990
--- /dev/null
+++ b/tests/baselines/reference/discriminantsAndPrimitives.symbols
@@ -0,0 +1,117 @@
+=== tests/cases/compiler/discriminantsAndPrimitives.ts ===
+
+// Repro from #10257 plus other tests
+
+interface Foo {
+>Foo : Symbol(Foo, Decl(discriminantsAndPrimitives.ts, 0, 0))
+
+    kind: "foo";
+>kind : Symbol(Foo.kind, Decl(discriminantsAndPrimitives.ts, 3, 15))
+
+    name: string;
+>name : Symbol(Foo.name, Decl(discriminantsAndPrimitives.ts, 4, 16))
+}
+
+interface Bar {
+>Bar : Symbol(Bar, Decl(discriminantsAndPrimitives.ts, 6, 1))
+
+    kind: "bar";
+>kind : Symbol(Bar.kind, Decl(discriminantsAndPrimitives.ts, 8, 15))
+
+    length: string;
+>length : Symbol(Bar.length, Decl(discriminantsAndPrimitives.ts, 9, 16))
+}
+
+function f1(x: Foo | Bar | string) {
+>f1 : Symbol(f1, Decl(discriminantsAndPrimitives.ts, 11, 1))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 13, 12))
+>Foo : Symbol(Foo, Decl(discriminantsAndPrimitives.ts, 0, 0))
+>Bar : Symbol(Bar, Decl(discriminantsAndPrimitives.ts, 6, 1))
+
+    if (typeof x !== 'string') {
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 13, 12))
+
+        switch(x.kind) {
+>x.kind : Symbol(kind, Decl(discriminantsAndPrimitives.ts, 3, 15), Decl(discriminantsAndPrimitives.ts, 8, 15))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 13, 12))
+>kind : Symbol(kind, Decl(discriminantsAndPrimitives.ts, 3, 15), Decl(discriminantsAndPrimitives.ts, 8, 15))
+
+            case 'foo':
+                x.name;
+>x.name : Symbol(Foo.name, Decl(discriminantsAndPrimitives.ts, 4, 16))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 13, 12))
+>name : Symbol(Foo.name, Decl(discriminantsAndPrimitives.ts, 4, 16))
+        }
+    }
+}
+
+function f2(x: Foo | Bar | string | undefined) {
+>f2 : Symbol(f2, Decl(discriminantsAndPrimitives.ts, 20, 1))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 22, 12))
+>Foo : Symbol(Foo, Decl(discriminantsAndPrimitives.ts, 0, 0))
+>Bar : Symbol(Bar, Decl(discriminantsAndPrimitives.ts, 6, 1))
+
+    if (typeof x === "object") {
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 22, 12))
+
+        switch(x.kind) {
+>x.kind : Symbol(kind, Decl(discriminantsAndPrimitives.ts, 3, 15), Decl(discriminantsAndPrimitives.ts, 8, 15))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 22, 12))
+>kind : Symbol(kind, Decl(discriminantsAndPrimitives.ts, 3, 15), Decl(discriminantsAndPrimitives.ts, 8, 15))
+
+            case 'foo':
+                x.name;
+>x.name : Symbol(Foo.name, Decl(discriminantsAndPrimitives.ts, 4, 16))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 22, 12))
+>name : Symbol(Foo.name, Decl(discriminantsAndPrimitives.ts, 4, 16))
+        }
+    }
+}
+
+function f3(x: Foo | Bar | string | null) {
+>f3 : Symbol(f3, Decl(discriminantsAndPrimitives.ts, 29, 1))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 31, 12))
+>Foo : Symbol(Foo, Decl(discriminantsAndPrimitives.ts, 0, 0))
+>Bar : Symbol(Bar, Decl(discriminantsAndPrimitives.ts, 6, 1))
+
+    if (x && typeof x !== "string") {
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 31, 12))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 31, 12))
+
+        switch(x.kind) {
+>x.kind : Symbol(kind, Decl(discriminantsAndPrimitives.ts, 3, 15), Decl(discriminantsAndPrimitives.ts, 8, 15))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 31, 12))
+>kind : Symbol(kind, Decl(discriminantsAndPrimitives.ts, 3, 15), Decl(discriminantsAndPrimitives.ts, 8, 15))
+
+            case 'foo':
+                x.name;
+>x.name : Symbol(Foo.name, Decl(discriminantsAndPrimitives.ts, 4, 16))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 31, 12))
+>name : Symbol(Foo.name, Decl(discriminantsAndPrimitives.ts, 4, 16))
+        }
+    }
+}
+
+function f4(x: Foo | Bar | string | number | null) {
+>f4 : Symbol(f4, Decl(discriminantsAndPrimitives.ts, 38, 1))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 40, 12))
+>Foo : Symbol(Foo, Decl(discriminantsAndPrimitives.ts, 0, 0))
+>Bar : Symbol(Bar, Decl(discriminantsAndPrimitives.ts, 6, 1))
+
+    if (x && typeof x === "object") {
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 40, 12))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 40, 12))
+
+        switch(x.kind) {
+>x.kind : Symbol(kind, Decl(discriminantsAndPrimitives.ts, 3, 15), Decl(discriminantsAndPrimitives.ts, 8, 15))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 40, 12))
+>kind : Symbol(kind, Decl(discriminantsAndPrimitives.ts, 3, 15), Decl(discriminantsAndPrimitives.ts, 8, 15))
+
+            case 'foo':
+                x.name;
+>x.name : Symbol(Foo.name, Decl(discriminantsAndPrimitives.ts, 4, 16))
+>x : Symbol(x, Decl(discriminantsAndPrimitives.ts, 40, 12))
+>name : Symbol(Foo.name, Decl(discriminantsAndPrimitives.ts, 4, 16))
+        }
+    }
+}
diff --git a/tests/baselines/reference/discriminantsAndPrimitives.types b/tests/baselines/reference/discriminantsAndPrimitives.types
new file mode 100644
index 00000000000..d3e1b70e599
--- /dev/null
+++ b/tests/baselines/reference/discriminantsAndPrimitives.types
@@ -0,0 +1,141 @@
+=== tests/cases/compiler/discriminantsAndPrimitives.ts ===
+
+// Repro from #10257 plus other tests
+
+interface Foo {
+>Foo : Foo
+
+    kind: "foo";
+>kind : "foo"
+
+    name: string;
+>name : string
+}
+
+interface Bar {
+>Bar : Bar
+
+    kind: "bar";
+>kind : "bar"
+
+    length: string;
+>length : string
+}
+
+function f1(x: Foo | Bar | string) {
+>f1 : (x: string | Foo | Bar) => void
+>x : string | Foo | Bar
+>Foo : Foo
+>Bar : Bar
+
+    if (typeof x !== 'string') {
+>typeof x !== 'string' : boolean
+>typeof x : string
+>x : string | Foo | Bar
+>'string' : "string"
+
+        switch(x.kind) {
+>x.kind : "foo" | "bar"
+>x : Foo | Bar
+>kind : "foo" | "bar"
+
+            case 'foo':
+>'foo' : "foo"
+
+                x.name;
+>x.name : string
+>x : Foo
+>name : string
+        }
+    }
+}
+
+function f2(x: Foo | Bar | string | undefined) {
+>f2 : (x: string | Foo | Bar | undefined) => void
+>x : string | Foo | Bar | undefined
+>Foo : Foo
+>Bar : Bar
+
+    if (typeof x === "object") {
+>typeof x === "object" : boolean
+>typeof x : string
+>x : string | Foo | Bar | undefined
+>"object" : "object"
+
+        switch(x.kind) {
+>x.kind : "foo" | "bar"
+>x : Foo | Bar
+>kind : "foo" | "bar"
+
+            case 'foo':
+>'foo' : "foo"
+
+                x.name;
+>x.name : string
+>x : Foo
+>name : string
+        }
+    }
+}
+
+function f3(x: Foo | Bar | string | null) {
+>f3 : (x: string | Foo | Bar | null) => void
+>x : string | Foo | Bar | null
+>Foo : Foo
+>Bar : Bar
+>null : null
+
+    if (x && typeof x !== "string") {
+>x && typeof x !== "string" : boolean | "" | null
+>x : string | Foo | Bar | null
+>typeof x !== "string" : boolean
+>typeof x : string
+>x : string | Foo | Bar
+>"string" : "string"
+
+        switch(x.kind) {
+>x.kind : "foo" | "bar"
+>x : Foo | Bar
+>kind : "foo" | "bar"
+
+            case 'foo':
+>'foo' : "foo"
+
+                x.name;
+>x.name : string
+>x : Foo
+>name : string
+        }
+    }
+}
+
+function f4(x: Foo | Bar | string | number | null) {
+>f4 : (x: string | number | Foo | Bar | null) => void
+>x : string | number | Foo | Bar | null
+>Foo : Foo
+>Bar : Bar
+>null : null
+
+    if (x && typeof x === "object") {
+>x && typeof x === "object" : boolean | "" | 0 | null
+>x : string | number | Foo | Bar | null
+>typeof x === "object" : boolean
+>typeof x : string
+>x : string | number | Foo | Bar
+>"object" : "object"
+
+        switch(x.kind) {
+>x.kind : "foo" | "bar"
+>x : Foo | Bar
+>kind : "foo" | "bar"
+
+            case 'foo':
+>'foo' : "foo"
+
+                x.name;
+>x.name : string
+>x : Foo
+>name : string
+        }
+    }
+}
diff --git a/tests/cases/compiler/discriminantsAndPrimitives.ts b/tests/cases/compiler/discriminantsAndPrimitives.ts
new file mode 100644
index 00000000000..6352d741808
--- /dev/null
+++ b/tests/cases/compiler/discriminantsAndPrimitives.ts
@@ -0,0 +1,49 @@
+// @strictNullChecks: true
+
+// Repro from #10257 plus other tests
+
+interface Foo {
+    kind: "foo";
+    name: string;
+}
+
+interface Bar {
+    kind: "bar";
+    length: string;
+}
+
+function f1(x: Foo | Bar | string) {
+    if (typeof x !== 'string') {
+        switch(x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+
+function f2(x: Foo | Bar | string | undefined) {
+    if (typeof x === "object") {
+        switch(x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+
+function f3(x: Foo | Bar | string | null) {
+    if (x && typeof x !== "string") {
+        switch(x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
+
+function f4(x: Foo | Bar | string | number | null) {
+    if (x && typeof x === "object") {
+        switch(x.kind) {
+            case 'foo':
+                x.name;
+        }
+    }
+}
\ No newline at end of file