Add tests

tests/cases/compiler/controlFlowArrayErrors.ts

@@ -0,0 +1,59 @@
+// @noImplicitAny: true
+
+declare function cond(): boolean;
+
+function f1() {
+    let x = [];
+    let y = x;  // Implicit any[] error
+    x.push(5);
+    let z = x;
+}
+
+function f2() {
+    let x;
+    x = [];
+    let y = x;  // Implicit any[] error
+    x.push(5);
+    let z = x;
+}
+
+function f3() {
+    let x = [];  // Implicit any[] error in some locations
+    x.push(5);
+    function g() {
+        x;  // Implicit any[] error
+    }
+}
+
+function f4() {
+    let x;
+    x = [5, "hello"];  // Non-evolving array
+    x.push(true);      // Error
+}
+
+function f5() {
+    let x = [5, "hello"];  // Non-evolving array
+    x.push(true);          // Error
+}
+
+function f6() {
+    let x;
+    if (cond()) {
+        x = [];
+        x.push(5);
+        x.push("hello");
+    }
+    else {
+        x = [true];  // Non-evolving array
+    }
+    x;           // boolean[] | (string | number)[]
+    x.push(99);  // Error
+}
+
+function f7() {
+    let x = [];       // x has evolving array value
+    x.push(5);
+    let y = x;        // y has non-evolving array value
+    x.push("hello");  // Ok
+    y.push("hello");  // Error
+}

tests/cases/compiler/controlFlowArrays.ts

@@ -0,0 +1,141 @@
+// @strictNullChecks: true
+// @noImplicitAny: true
+
+declare function cond(): boolean;
+
+function f1() {
+    let x = [];
+    x[0] = 5;
+    x[1] = "hello";
+    x[2] = true;
+    return x;  // (string | number | boolean)[]
+}
+
+function f2() {
+    let x = [];
+    x.push(5);
+    x.push("hello");
+    x.push(true);
+    return x;  // (string | number | boolean)[]
+}
+
+function f3() {
+    let x;
+    x = [];
+    x.push(5, "hello");
+    return x;  // (string | number)[]
+}
+
+function f4() {
+    let x = [];
+    if (cond()) {
+        x.push(5);
+    }
+    else {
+        x.push("hello");
+    }
+    return x;  // (string | number)[]
+}
+
+function f5() {
+    let x;
+    if (cond()) {
+        x = [];
+        x.push(5);
+    }
+    else {
+        x = [];
+        x.push("hello");
+    }
+    return x;  // (string | number)[]
+}
+
+function f6() {
+    let x;
+    if (cond()) {
+        x = 5;
+    }
+    else {
+        x = [];
+        x.push("hello");
+    }
+    return x;  // number | string[]
+}
+
+function f7() {
+    let x = null;
+    if (cond()) {
+        x = [];
+        while (cond()) {
+            x.push("hello");
+        }
+    }
+    return x;  // string[] | null
+}
+
+function f8() {
+    let x = [];
+    x.push(5);
+    if (cond()) return x;  // number[]
+    x.push("hello");
+    if (cond()) return x;  // (string | number)[]
+    x.push(true);
+    return x;  // (string | number | boolean)[]
+}
+
+function f9() {
+    let x = [];
+    if (cond()) {
+        x.push(5);
+        return x;  // number[]
+    }
+    else {
+        x.push("hello");
+        return x;  // string[]
+    }
+}
+
+function f10() {
+    let x = [];
+    if (cond()) {
+        x.push(true);
+        x;  // boolean[]
+    }
+    else {
+        x.push(5);
+        x;  // number[]
+        while (cond()) {
+            x.push("hello");
+        }
+        x;  // (string | number)[]
+    }
+    x.push(99);
+    return x;  // (string | number | boolean)[]
+}
+
+function f11() {
+    let x = [];
+    return x;  // never[]
+}
+
+function f12() {
+    let x;
+    x = [];
+    return x;  // never[]
+}
+
+function f13() {
+    var x = [];
+    x.push(5);
+    x.push("hello");
+    x.push(true);
+    return x;  // (string | number | boolean)[]
+}
+
+function f14() {
+    const x = [];
+    x.push(5);
+    x.push("hello");
+    x.push(true);
+    return x;  // (string | number | boolean)[]
+}