diff --git a/tests/cases/conformance/controlFlow/controlFlowAssignmentExpression.ts b/tests/cases/conformance/controlFlow/controlFlowAssignmentExpression.ts
new file mode 100644
index 0000000000000..83bf75ab94d0c
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowAssignmentExpression.ts
@@ -0,0 +1,10 @@
+let x: string | boolean | number;
+let obj: any;
+
+x = "";
+x = x.length;
+x; // number
+
+x = true;
+(x = "", obj).foo = (x = x.length);
+x; // number
diff --git a/tests/cases/conformance/controlFlow/controlFlowBinaryAndExpression.ts b/tests/cases/conformance/controlFlow/controlFlowBinaryAndExpression.ts
new file mode 100644
index 0000000000000..caaef9b890f52
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowBinaryAndExpression.ts
@@ -0,0 +1,9 @@
+let x: string | number | boolean;
+let cond: boolean;
+
+(x = "") && (x = 0);
+x; // string | number
+
+x = "";
+cond && (x = 0);
+x; // string | number
diff --git a/tests/cases/conformance/controlFlow/controlFlowBinaryOrExpression.ts b/tests/cases/conformance/controlFlow/controlFlowBinaryOrExpression.ts
new file mode 100644
index 0000000000000..75b24622e0028
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowBinaryOrExpression.ts
@@ -0,0 +1,9 @@
+let x: string | number | boolean;
+let cond: boolean;
+
+(x = "") || (x = 0);
+x; // string | number
+
+x = "";
+cond || (x = 0);
+x; // string | number
diff --git a/tests/cases/conformance/controlFlow/controlFlowConditionalExpression.ts b/tests/cases/conformance/controlFlow/controlFlowConditionalExpression.ts
new file mode 100644
index 0000000000000..c1c1d9956ea05
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowConditionalExpression.ts
@@ -0,0 +1,5 @@
+let x: string | number | boolean;
+let cond: boolean;
+
+cond ? x = "" : x = 3;
+x; // string | number
diff --git a/tests/cases/conformance/controlFlow/controlFlowDoWhileStatement.ts b/tests/cases/conformance/controlFlow/controlFlowDoWhileStatement.ts
new file mode 100644
index 0000000000000..bd253bc064def
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowDoWhileStatement.ts
@@ -0,0 +1,76 @@
+let cond: boolean;
+function a() {
+    let x: string | number;
+    x = "";
+    do {
+        x; // string
+    } while (cond)
+}
+function b() {
+    let x: string | number;
+    x = "";
+    do {
+        x; // string
+        x = 42;
+        break;
+    } while (cond)
+}
+function c() {
+    let x: string | number;
+    x = "";
+    do {
+        x; // string
+        x = undefined;
+        if (typeof x === "string") continue;
+        break;
+    } while (cond)
+}
+function d() {
+    let x: string | number;
+    x = 1000;
+    do {
+        x; // number
+        x = "";
+    } while (x = x.length)
+    x; // number
+}
+function e() {
+    let x: string | number;
+    x = "";
+    do {
+        x = 42;
+    } while (cond)
+    x; // number
+}
+function f() {
+    let x: string | number | boolean | RegExp | Function;
+    x = "";
+    do {
+        if (cond) {
+            x = 42;
+            break;
+        }
+        if (cond) {
+            x = true;
+            continue;
+        }
+        x = /a/;
+    } while (cond)
+    x; // number | boolean | RegExp
+}
+function g() {
+    let x: string | number | boolean | RegExp | Function;
+    x = "";
+    do {
+        if (cond) {
+            x = 42;
+            break;
+        }
+        if (cond) {
+            x = true;
+            continue;
+        }
+        x = /a/;
+    } while (true)
+    x; // number
+}
diff --git a/tests/cases/conformance/controlFlow/controlFlowForInStatement.ts b/tests/cases/conformance/controlFlow/controlFlowForInStatement.ts
new file mode 100644
index 0000000000000..a22e79506c250
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowForInStatement.ts
@@ -0,0 +1,17 @@
+let x: string | number | boolean | RegExp | Function;
+let obj: any;
+let cond: boolean;
+
+x = /a/;
+for (let y in obj) {
+    x = y;
+    if (cond) {
+        x = 42;
+        continue;
+    }
+    if (cond) {
+        x = true;
+        break;
+    }
+}
+x; // RegExp | string | number | boolean
diff --git a/tests/cases/conformance/controlFlow/controlFlowForOfStatement.ts b/tests/cases/conformance/controlFlow/controlFlowForOfStatement.ts
new file mode 100644
index 0000000000000..ac4c584e1dcae
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowForOfStatement.ts
@@ -0,0 +1,10 @@
+let obj: number[];
+let x: string | number | boolean | RegExp;
+
+function a() {
+    x = true;
+    for (x of obj) {
+        x = x.toExponential();
+    }
+    x; // number | boolean
+}
diff --git a/tests/cases/conformance/controlFlow/controlFlowForStatement.ts b/tests/cases/conformance/controlFlow/controlFlowForStatement.ts
new file mode 100644
index 0000000000000..d9e46781aa7b5
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowForStatement.ts
@@ -0,0 +1,41 @@
+let cond: boolean;
+function a() {
+    let x: string | number | boolean;
+    for (x = ""; cond; x = 5) {
+        x; // string | number
+    }
+}
+function b() {
+    let x: string | number | boolean;
+    for (x = 5; cond; x = x.length) {
+        x; // number
+        x = "";
+    }
+}
+function c() {
+    let x: string | number | boolean;
+    for (x = 5; x = x.toExponential(); x = 5) {
+        x; // string
+    }
+}
+function d() {
+    let x: string | number | boolean;
+    for (x = ""; typeof x === "string"; x = 5) {
+        x; // string
+    }
+}
+function e() {
+    let x: string | number | boolean | RegExp;
+    for (x = "" || 0; typeof x !== "string"; x = "" || true) {
+        x; // number | boolean
+    }
+}
+function f() {
+    let x: string | number | boolean;
+    for (; typeof x !== "string";) {
+        x; // number | boolean
+        if (typeof x === "number") break;
+        x = undefined;
+    }
+    x; // string | number
+}
diff --git a/tests/cases/conformance/controlFlow/controlFlowIfStatement.ts b/tests/cases/conformance/controlFlow/controlFlowIfStatement.ts
new file mode 100644
index 0000000000000..c9e9be92f8e7e
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowIfStatement.ts
@@ -0,0 +1,36 @@
+let x: string | number | boolean | RegExp;
+let cond: boolean;
+
+x = /a/;
+if (x /* RegExp */, (x = true)) {
+    x; // boolean
+    x = "";
+}
+else {
+    x; // boolean
+    x = 42;
+}
+x; // string | number
+
+function a() {
+    let x: string | number;
+    if (cond) {
+        x = 42;
+    }
+    else {
+        x = "";
+        return;
+    }
+    x; // number
+}
+function b() {
+    let x: string | number;
+    if (cond) {
+        x = 42;
+        throw "";
+    }
+    else {
+        x = "";
+    }
+    x; // string
+}
diff --git a/tests/cases/conformance/controlFlow/controlFlowWhileStatement.ts b/tests/cases/conformance/controlFlow/controlFlowWhileStatement.ts
new file mode 100644
index 0000000000000..697a867b88689
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowWhileStatement.ts
@@ -0,0 +1,75 @@
+let cond: boolean;
+function a() {
+    let x: string | number;
+    x = "";
+    while (cond) {
+        x; // string
+    }
+}
+function b() {
+    let x: string | number;
+    x = "";
+    while (cond) {
+        x; // string
+        x = 42;
+        break;
+    }
+}
+function c() {
+    let x: string | number;
+    x = "";
+    while (cond) {
+        x; // string
+        x = undefined;
+        if (typeof x === "string") continue;
+        break;
+    }
+}
+function d() {
+    let x: string | number;
+    x = "";
+    while (x = x.length) {
+        x; // number
+        x = "";
+    }
+}
+function e() {
+    let x: string | number;
+    x = "";
+    while (cond) {
+        x = 42;
+    }
+    x; // string | number
+}
+function f() {
+    let x: string | number | boolean | RegExp | Function;
+    x = "";
+    while (cond) {
+        if (cond) {
+            x = 42;
+            break;
+        }
+        if (cond) {
+            x = true;
+            continue;
+        }
+        x = /a/;
+    }
+    x; // string | number | boolean | RegExp
+}
+function g() {
+    let x: string | number | boolean | RegExp | Function;
+    x = "";
+    while (true) {
+        if (cond) {
+            x = 42;
+            break;
+        }
+        if (cond) {
+            x = true;
+            continue;
+        }
+        x = /a/;
+    }
+    x; // number
+}
diff --git a/tests/cases/conformance/expressions/assignmentOperator/assignmentTypeNarrowing.ts b/tests/cases/conformance/expressions/assignmentOperator/assignmentTypeNarrowing.ts
new file mode 100644
index 0000000000000..0e5e257635a57
--- /dev/null
+++ b/tests/cases/conformance/expressions/assignmentOperator/assignmentTypeNarrowing.ts
@@ -0,0 +1,28 @@
+let x: string | number | boolean | RegExp;
+
+x = "";
+x; // string
+
+[x] = [true];
+x; // boolean
+
+[x = ""] = [1];
+x; // string | number
+
+({x} = {x: true});
+x; // boolean
+
+({y: x} = {y: 1});
+x; // number
+
+({x = ""} = {x: true});
+x; // string | boolean
+
+({y: x = /a/} = {y: 1});
+x; // number | RegExp
+
+let a: string[];
+
+for (x of a) {
+    x; // string
+}
diff --git a/tests/cases/conformance/expressions/typeGuards/typeGuardsInDoStatement.ts b/tests/cases/conformance/expressions/typeGuards/typeGuardsInDoStatement.ts
new file mode 100644
index 0000000000000..1afbe515df8d4
--- /dev/null
+++ b/tests/cases/conformance/expressions/typeGuards/typeGuardsInDoStatement.ts
@@ -0,0 +1,27 @@
+let cond: boolean;
+function a(x: string | number | boolean) {
+    x = true;
+    do {
+        x; // boolean | string
+        x = undefined;
+    } while (typeof x === "string")
+    x; // number | boolean
+}
+function b(x: string | number | boolean) {
+    x = true;
+    do {
+        x; // boolean | string
+        if (cond) continue;
+        x = undefined;
+    } while (typeof x === "string")
+    x; // number | boolean
+}
+function c(x: string | number) {
+    x = "";
+    do {
+        x; // string
+        if (cond) break;
+        x = undefined;
+    } while (typeof x === "string")
+    x; // string | number
+}
diff --git a/tests/cases/conformance/expressions/typeGuards/typeGuardsInForStatement.ts b/tests/cases/conformance/expressions/typeGuards/typeGuardsInForStatement.ts
new file mode 100644
index 0000000000000..cf5c008e80050
--- /dev/null
+++ b/tests/cases/conformance/expressions/typeGuards/typeGuardsInForStatement.ts
@@ -0,0 +1,21 @@
+let cond: boolean;
+function a(x: string | number) {
+    for (x = undefined; typeof x !== "number"; x = undefined) {
+        x; // string
+    }
+    x; // number
+}
+function b(x: string | number) {
+    for (x = undefined; typeof x !== "number"; x = undefined) {
+        x; // string
+        if (cond) continue;
+    }
+    x; // number
+}
+function c(x: string | number) {
+    for (x = undefined; typeof x !== "number"; x = undefined) {
+        x; // string
+        if (cond) break;
+    }
+    x; // string | number
+}
diff --git a/tests/cases/conformance/expressions/typeGuards/typeGuardsInWhileStatement.ts b/tests/cases/conformance/expressions/typeGuards/typeGuardsInWhileStatement.ts
new file mode 100644
index 0000000000000..642c899579531
--- /dev/null
+++ b/tests/cases/conformance/expressions/typeGuards/typeGuardsInWhileStatement.ts
@@ -0,0 +1,24 @@
+let cond: boolean;
+function a(x: string | number) {
+    while (typeof x === "string") {
+        x; // string
+        x = undefined;
+    }
+    x; // number
+}
+function b(x: string | number) {
+    while (typeof x === "string") {
+        if (cond) continue;
+        x; // string
+        x = undefined;
+    }
+    x; // number
+}
+function c(x: string | number) {
+    while (typeof x === "string") {
+        if (cond) break;
+        x; // string
+        x = undefined;
+    }
+    x; // string | number
+}