Close iterator after error in Array.from

Issue #17

1 files changed, 183 insertions, 0 deletions

diff --git a/js/src/tests/ecma_6/Array/from-iterator-close.js b/js/src/tests/ecma_6/Array/from-iterator-close.js
new file mode 100644
index 000000000..fa97ea282
--- /dev/null
+++ b/js/src/tests/ecma_6/Array/from-iterator-close.js
@@ -0,0 +1,183 @@
+var BUGNUMBER = 1180306;
+var summary = 'Array.from should close iterator on error';
+
+print(BUGNUMBER + ": " + summary);
+
+function test(ctor, { mapVal=undefined,
+                      nextVal=undefined,
+                      nextThrowVal=undefined,
+                      modifier=undefined,
+                      exceptionVal=undefined,
+                      exceptionType=undefined,
+                      closed=true }) {
+    let iterable = {
+        closed: false,
+        [Symbol.iterator]() {
+            let iterator = {
+                first: true,
+                next() {
+                    if (this.first) {
+                        this.first = false;
+                        if (nextThrowVal)
+                            throw nextThrowVal;
+                        return nextVal;
+                    }
+                    return { value: undefined, done: true };
+                },
+                return() {
+                    iterable.closed = true;
+                    return {};
+                }
+            };
+            if (modifier)
+                modifier(iterator, iterable);
+
+            return iterator;
+        }
+    };
+    if (exceptionVal) {
+        let caught = false;
+        try {
+            ctor.from(iterable, mapVal);
+        } catch (e) {
+            assertEq(e, exceptionVal);
+            caught = true;
+        }
+        assertEq(caught, true);
+    } else if (exceptionType) {
+        assertThrowsInstanceOf(() => ctor.from(iterable, mapVal), exceptionType);
+    } else {
+        ctor.from(iterable, mapVal);
+    }
+    assertEq(iterable.closed, closed);
+}
+
+// == Error cases with close ==
+
+// ES 2017 draft 22.1.2.1 step 5.e.i.1.
+// Cannot test.
+
+// ES 2017 draft 22.1.2.1 step 5.e.vi.2.
+test(Array, {
+    mapVal: () => { throw "map throws"; },
+    nextVal: { value: 1, done: false },
+    exceptionVal: "map throws",
+    closed: true,
+});
+
+// ES 2017 draft 22.1.2.1 step 5.e.ix.
+class MyArray extends Array {
+    constructor() {
+        return new Proxy({}, {
+            defineProperty() {
+                throw "defineProperty throws";
+            }
+        });
+    }
+}
+test(MyArray, {
+    nextVal: { value: 1, done: false },
+    exceptionVal: "defineProperty throws",
+    closed: true,
+});
+
+// ES 2017 draft 7.4.6 step 3.
+// if GetMethod fails, the thrown value should be used.
+test(MyArray, {
+    nextVal: { value: 1, done: false },
+    modifier: (iterator, iterable) => {
+        Object.defineProperty(iterator, "return", {
+            get: function() {
+                iterable.closed = true;
+                throw "return getter throws";
+            }
+        });
+    },
+    exceptionVal: "return getter throws",
+    closed: true,
+});
+test(MyArray, {
+    nextVal: { value: 1, done: false },
+    modifier: (iterator, iterable) => {
+        Object.defineProperty(iterator, "return", {
+            get: function() {
+                iterable.closed = true;
+                return "non object";
+            }
+        });
+    },
+    exceptionType: TypeError,
+    closed: true,
+});
+test(MyArray, {
+    nextVal: { value: 1, done: false },
+    modifier: (iterator, iterable) => {
+        Object.defineProperty(iterator, "return", {
+            get: function() {
+                iterable.closed = true;
+                // Non callable.
+                return {};
+            }
+        });
+    },
+    exceptionType: TypeError,
+    closed: true,
+});
+
+// ES 2017 draft 7.4.6 steps 6.
+// if return method throws, the thrown value should be ignored.
+test(MyArray, {
+    nextVal: { value: 1, done: false },
+    modifier: (iterator, iterable) => {
+        iterator.return = function() {
+            iterable.closed = true;
+            throw "return throws";
+        };
+    },
+    exceptionVal: "defineProperty throws",
+    closed: true,
+});
+
+test(MyArray, {
+    nextVal: { value: 1, done: false },
+    modifier: (iterator, iterable) => {
+        iterator.return = function() {
+            iterable.closed = true;
+            return "non object";
+        };
+    },
+    exceptionVal: "defineProperty throws",
+    closed: true,
+});
+
+// == Error cases without close ==
+
+// ES 2017 draft 22.1.2.1 step 5.e.iii.
+test(Array, {
+    nextThrowVal: "next throws",
+    exceptionVal: "next throws",
+    closed: false,
+});
+
+test(Array, {
+    nextVal: { value: {}, get done() { throw "done getter throws"; } },
+    exceptionVal: "done getter throws",
+    closed: false,
+});
+
+// ES 2017 draft 22.1.2.1 step 5.e.v.
+test(Array, {
+    nextVal: { get value() { throw "value getter throws"; }, done: false },
+    exceptionVal: "value getter throws",
+    closed: false,
+});
+
+// == Successful cases ==
+
+test(Array, {
+    nextVal: { value: 1, done: false },
+    closed: false,
+});
+
+if (typeof reportCompare === 'function')
+  reportCompare(true, true);