LibJS: Don't handle arrays separately in Value::to_number()

Now that Array.prototype.join() is producing the correct results we
can remove the separate code path for arrays in Value::to_number()
and treat them like all other objects - using to_primitive() with
number as the preferred type and then calling to_number() on the
result.

This is how the spec descibes it.

This also means we don't crash anymore when trying to coerce
[<empty>] to a number - it now does the following:

[<empty>] - to string - "" - to number - 0
[<empty>, <empty>] - to string - "," - to number - NaN

1 files changed, 12 insertions, 2 deletions

diff --git a/Libraries/LibJS/Tests/to-number-basic.js b/Libraries/LibJS/Tests/to-number-basic.js
index e0d07a51fe..902ad293f2 100644
--- a/Libraries/LibJS/Tests/to-number-basic.js
+++ b/Libraries/LibJS/Tests/to-number-basic.js
@@ -9,6 +9,12 @@ try {
     assert(-null === 0);
     assert(+[] === 0);
     assert(-[] === 0);
+    assert(+[,] === 0);
+    assert(-[,] === 0);
+    assert(+[null] === 0);
+    assert(-[null] === 0);
+    assert(+[undefined] === 0);
+    assert(-[undefined] === 0);
     assert(+[[[[[]]]]] === 0);
     assert(-[[[[[]]]]] === 0);
     assert(+[[[[[42]]]]] === 42);
@@ -35,8 +41,12 @@ try {
     assert(isNaN(-undefined));
     assert(isNaN(+{}));
     assert(isNaN(-{}));
-    assert(isNaN(+{a: 1}));
-    assert(isNaN(-{a: 1}));
+    assert(isNaN(+{ a: 1 }));
+    assert(isNaN(-{ a: 1 }));
+    assert(isNaN(+[, , ,]));
+    assert(isNaN(-[, , ,]));
+    assert(isNaN(+[undefined, undefined]));
+    assert(isNaN(-[undefined, undefined]));
     assert(isNaN(+[1, 2, 3]));
     assert(isNaN(-[1, 2, 3]));
     assert(isNaN(+[[[["foo"]]]]));