fix externalization of empty typed arrays (fixes #597)

flimzy · neelance · commit 96e2b0e61b74 · 2017-02-26T19:41:12.000+01:00
diff --git a/compiler/prelude/prelude.go b/compiler/prelude/prelude.go
@@ -119,9 +119,6 @@ var $substring = function(str, low, high) {
 };
 
 var $sliceToArray = function(slice) {
-  if (slice.$length === 0) {
-    return [];
-  }
   if (slice.$array.constructor !== Array) {
     return slice.$array.subarray(slice.$offset, slice.$offset + slice.$length);
   }
diff --git a/js/js_test.go b/js/js_test.go
@@ -43,6 +43,9 @@ var dummys = js.Global.Call("eval", `({
 	call: function(f, a) {
 		f(a);
 	},
+	return: function(x) {
+		return x;
+	},
 })`)
 
 func TestBool(t *testing.T) {
@@ -558,3 +561,13 @@ func TestSurrogatePairs(t *testing.T) {
 		t.Fail()
 	}
 }
+
+func TestUint8Array(t *testing.T) {
+	uint8Array := js.Global.Get("Uint8Array")
+	if dummys.Call("return", []byte{}).Get("constructor") != uint8Array {
+		t.Errorf("Empty byte array is not externalized as a Uint8Array")
+	}
+	if dummys.Call("return", []byte{0x01}).Get("constructor") != uint8Array {
+		t.Errorf("Non-empty byte array is not externalized as a Uint8Array")
+	}
+}
diff --git a/tests/deferblock_test.go b/tests/deferblock_test.go
@@ -26,7 +26,7 @@ func outer(ch chan struct{}, b bool) ([]byte, error) {
 func TestBlockingInDefer(t *testing.T) {
 	defer func() {
 		if x := recover(); x != nil {
-			t.Error("run time panic: %v", x)
+			t.Errorf("run time panic: %v", x)
 		}
 	}()
 

Original file line number	Diff line number	Diff line change
`@@ -119,9 +119,6 @@ var $substring = function(str, low, high) {`
`119`	`119`	`};`
`120`	`120`
`121`	`121`	`var $sliceToArray = function(slice) {`
`122`		`- if (slice.$length === 0) {`
`123`		`- return [];`
`124`		`- }`
`125`	`122`	`if (slice.$array.constructor !== Array) {`
`126`	`123`	`return slice.$array.subarray(slice.$offset, slice.$offset + slice.$length);`
`127`	`124`	`}`
Original file line number	Diff line number	Diff line change
`@@ -26,7 +26,7 @@ func outer(ch chan struct{}, b bool) ([]byte, error) {`
`26`	`26`	`func TestBlockingInDefer(t *testing.T) {`
`27`	`27`	`defer func() {`
`28`	`28`	`if x := recover(); x != nil {`
`29`		`- t.Error("run time panic: %v", x)`
	`29`	`+ t.Errorf("run time panic: %v", x)`
`30`	`30`	`}`
`31`	`31`	`}()`
`32`	`32`