diff --git a/tests/cases/conformance/expressions/asOperator/asOperator1.ts b/tests/cases/conformance/expressions/asOperator/asOperator1.ts
new file mode 100644
index 0000000000..cf953d75ab
--- /dev/null
+++ b/tests/cases/conformance/expressions/asOperator/asOperator1.ts
@@ -0,0 +1,8 @@
+var as = 43;
+var x = undefined as number;
+var y = (null as string).length;
+var z = Date as any as string;
+
+// Should parse as a union type, not a bitwise 'or' of (32 as number) and 'string'
+var j = 32 as number|string;
+j = '';
diff --git a/tests/cases/conformance/expressions/asOperator/asOperator2.ts b/tests/cases/conformance/expressions/asOperator/asOperator2.ts
new file mode 100644
index 0000000000..1fa5f2c938
--- /dev/null
+++ b/tests/cases/conformance/expressions/asOperator/asOperator2.ts
@@ -0,0 +1 @@
+var x = 23 as string;
diff --git a/tests/cases/conformance/expressions/asOperator/asOperator3.ts b/tests/cases/conformance/expressions/asOperator/asOperator3.ts
new file mode 100644
index 0000000000..4c136247e0
--- /dev/null
+++ b/tests/cases/conformance/expressions/asOperator/asOperator3.ts
@@ -0,0 +1,10 @@
+declare function tag(...x: any[]): any;
+
+var a = `${123 + 456 as number}`;
+var b = `leading ${123 + 456 as number}`;
+var c = `${123 + 456 as number} trailing`;
+var d = `Hello ${123} World` as string;
+var e = `Hello` as string;
+var f = 1 + `${1} end of string` as string;
+var g = tag `Hello ${123} World` as string;
+var h = tag `Hello` as string;
\ No newline at end of file
diff --git a/tests/cases/conformance/expressions/asOperator/asOperatorASI.ts b/tests/cases/conformance/expressions/asOperator/asOperatorASI.ts
new file mode 100644
index 0000000000..a4dd44a15a
--- /dev/null
+++ b/tests/cases/conformance/expressions/asOperator/asOperatorASI.ts
@@ -0,0 +1,10 @@
+class Foo { }
+declare function as(...args: any[]);
+
+// Example 1
+var x = 10
+as `Hello world`; // should not error
+
+// Example 2
+var y = 20
+as(Foo); // should emit
diff --git a/tests/cases/conformance/expressions/asOperator/asOperatorAmbiguity.ts b/tests/cases/conformance/expressions/asOperator/asOperatorAmbiguity.ts
new file mode 100644
index 0000000000..e4921314ba
--- /dev/null
+++ b/tests/cases/conformance/expressions/asOperator/asOperatorAmbiguity.ts
@@ -0,0 +1,8 @@
+interface A<T> { x: T; }
+interface B { m: string; }
+
+// Make sure this is a type assertion to an array type, and not nested comparison operators.
+var x: any;
+var y = x as A<B>[];
+var z = y[0].m; // z should be string
+
diff --git a/tests/cases/conformance/expressions/asOperator/asOperatorContextualType.ts b/tests/cases/conformance/expressions/asOperator/asOperatorContextualType.ts
new file mode 100644
index 0000000000..d3a23e224b
--- /dev/null
+++ b/tests/cases/conformance/expressions/asOperator/asOperatorContextualType.ts
@@ -0,0 +1,2 @@
+// should error
+var x = (v => v) as (x: number) => string;
\ No newline at end of file
diff --git a/tests/cases/conformance/expressions/asOperator/asOperatorNames.ts b/tests/cases/conformance/expressions/asOperator/asOperatorNames.ts
new file mode 100644
index 0000000000..a0b54d43e8
--- /dev/null
+++ b/tests/cases/conformance/expressions/asOperator/asOperatorNames.ts
@@ -0,0 +1,4 @@
+var a = 20;
+var b = a as string;
+var as = "hello";
+var as1 = as as string;