test: add a test for array non null inference

thanks to @Andarist for providing this test!

Author: nicolas377

tests/baselines/reference/nonNullFullInference.js

@@ -12,8 +12,25 @@ function testNonNullInference(numbers: number[]) {
         last = n;
     }
 
-    last; // number
-    last!; // number
+    last;
+    last!;
+}
+
+function testNonNullInferenceWithArrays(numbers: number[]) {
+    let result;
+    const arr = [];
+
+    for (const n of numbers) {
+        if (n % 2) {
+            return [n];
+        }
+
+        arr.push(n);
+        result = arr;
+    }
+
+    result;
+    result!;
 }
 
 //// [nonNullFullInference.js]
@@ -27,6 +44,20 @@ function testNonNullInference(numbers) {
         }
         last = n;
     }
-    last; // number
-    last; // number
+    last;
+    last;
+}
+function testNonNullInferenceWithArrays(numbers) {
+    var result;
+    var arr = [];
+    for (var _i = 0, numbers_2 = numbers; _i < numbers_2.length; _i++) {
+        var n = numbers_2[_i];
+        if (n % 2) {
+            return [n];
+        }
+        arr.push(n);
+        result = arr;
+    }
+    result;
+    result;
 }

tests/baselines/reference/nonNullFullInference.symbols

@@ -24,9 +24,48 @@ function testNonNullInference(numbers: number[]) {
 >n : Symbol(n, Decl(nonNullFullInference.ts, 5, 14))
     }
 
-    last; // number
+    last;
 >last : Symbol(last, Decl(nonNullFullInference.ts, 3, 7))
 
-    last!; // number
+    last!;
 >last : Symbol(last, Decl(nonNullFullInference.ts, 3, 7))
 }
+
+function testNonNullInferenceWithArrays(numbers: number[]) {
+>testNonNullInferenceWithArrays : Symbol(testNonNullInferenceWithArrays, Decl(nonNullFullInference.ts, 15, 1))
+>numbers : Symbol(numbers, Decl(nonNullFullInference.ts, 17, 40))
+
+    let result;
+>result : Symbol(result, Decl(nonNullFullInference.ts, 18, 7))
+
+    const arr = [];
+>arr : Symbol(arr, Decl(nonNullFullInference.ts, 19, 9))
+
+    for (const n of numbers) {
+>n : Symbol(n, Decl(nonNullFullInference.ts, 21, 14))
+>numbers : Symbol(numbers, Decl(nonNullFullInference.ts, 17, 40))
+
+        if (n % 2) {
+>n : Symbol(n, Decl(nonNullFullInference.ts, 21, 14))
+
+            return [n];
+>n : Symbol(n, Decl(nonNullFullInference.ts, 21, 14))
+        }
+
+        arr.push(n);
+>arr.push : Symbol(Array.push, Decl(lib.es5.d.ts, --, --))
+>arr : Symbol(arr, Decl(nonNullFullInference.ts, 19, 9))
+>push : Symbol(Array.push, Decl(lib.es5.d.ts, --, --))
+>n : Symbol(n, Decl(nonNullFullInference.ts, 21, 14))
+
+        result = arr;
+>result : Symbol(result, Decl(nonNullFullInference.ts, 18, 7))
+>arr : Symbol(arr, Decl(nonNullFullInference.ts, 19, 9))
+    }
+
+    result;
+>result : Symbol(result, Decl(nonNullFullInference.ts, 18, 7))
+
+    result!;
+>result : Symbol(result, Decl(nonNullFullInference.ts, 18, 7))
+}

tests/baselines/reference/nonNullFullInference.types

@@ -27,10 +27,56 @@ function testNonNullInference(numbers: number[]) {
 >n : number
     }
 
-    last; // number
+    last;
 >last : number
 
-    last!; // number
+    last!;
 >last! : number
 >last : number
 }
+
+function testNonNullInferenceWithArrays(numbers: number[]) {
+>testNonNullInferenceWithArrays : (numbers: number[]) => number[]
+>numbers : number[]
+
+    let result;
+>result : any
+
+    const arr = [];
+>arr : any[]
+>[] : undefined[]
+
+    for (const n of numbers) {
+>n : number
+>numbers : number[]
+
+        if (n % 2) {
+>n % 2 : number
+>n : number
+>2 : 2
+
+            return [n];
+>[n] : number[]
+>n : number
+        }
+
+        arr.push(n);
+>arr.push(n) : number
+>arr.push : (...items: any[]) => number
+>arr : any[]
+>push : (...items: any[]) => number
+>n : number
+
+        result = arr;
+>result = arr : number[]
+>result : any
+>arr : number[]
+    }
+
+    result;
+>result : number[]
+
+    result!;
+>result! : number[]
+>result : number[]
+}

tests/cases/compiler/nonNullFullInference.ts

@@ -12,6 +12,23 @@ function testNonNullInference(numbers: number[]) {
         last = n;
     }
 
-    last; // number
-    last!; // number
+    last;
+    last!;
+}
+
+function testNonNullInferenceWithArrays(numbers: number[]) {
+    let result;
+    const arr = [];
+
+    for (const n of numbers) {
+        if (n % 2) {
+            return [n];
+        }
+
+        arr.push(n);
+        result = arr;
+    }
+
+    result;
+    result!;
 }