diff options
| -rw-r--r-- | lib/compress.js | 7 | ||||
| -rw-r--r-- | test/compress/issue-2871.js | 37 |
2 files changed, 43 insertions, 1 deletions
diff --git a/lib/compress.js b/lib/compress.js index 321ee5fc..a48d0c9a 100644 --- a/lib/compress.js +++ b/lib/compress.js @@ -4790,6 +4790,7 @@ merge(Compressor.prototype, { if (compressor.option("comparisons")) switch (self.operator) { case "===": case "!==": + var is_strict_comparison = true; if ((self.left.is_string(compressor) && self.right.is_string(compressor)) || (self.left.is_number(compressor) && self.right.is_number(compressor)) || (self.left.is_boolean() && self.right.is_boolean()) || @@ -4799,8 +4800,12 @@ merge(Compressor.prototype, { // XXX: intentionally falling down to the next case case "==": case "!=": + // void 0 == x => null == x + if (!is_strict_comparison && is_undefined(self.left, compressor)) { + self.left = make_node(AST_Null, self.left); + } // "undefined" == typeof x => undefined === x - if (compressor.option("typeofs") + else if (compressor.option("typeofs") && self.left instanceof AST_String && self.left.value == "undefined" && self.right instanceof AST_UnaryPrefix diff --git a/test/compress/issue-2871.js b/test/compress/issue-2871.js new file mode 100644 index 00000000..43c8352b --- /dev/null +++ b/test/compress/issue-2871.js @@ -0,0 +1,37 @@ +comparison_with_undefined: { + options = { + comparisons: true, + } + input: { + a == undefined; + a != undefined; + a === undefined; + a !== undefined; + + undefined == a; + undefined != a; + undefined === a; + undefined !== a; + + void 0 == a; + void 0 != a; + void 0 === a; + void 0 !== a; + } + expect: { + null == a; + null != a; + void 0 === a; + void 0 !== a; + + null == a; + null != a; + void 0 === a; + void 0 !== a; + + null == a; + null != a; + void 0 === a; + void 0 !== a; + } +} |