fix(minifier): incorrect minification in try_fold_left_child_op (#7949

) fixes #7944
oxc-project · Dec 17, 2024 · de8a86e · de8a86e
1 parent e0d440a
commit de8a86e
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diff --git a/crates/oxc_minifier/src/ast_passes/peephole_fold_constants.rs b/crates/oxc_minifier/src/ast_passes/peephole_fold_constants.rs
@@ -258,6 +258,9 @@ impl<'a, 'b> PeepholeFoldConstants {
         let Expression::BinaryExpression(left) = &mut e.left else {
             return None;
         };
+        if left.operator != op {
+            return None;
+        }
 
         let (v, expr_to_move);
         if let Some(result) = ctx.eval_binary_operation(op, &left.left, &e.right) {
@@ -1276,6 +1279,13 @@ mod test {
         test("x = null & 1", "x = 0");
         test("x = (2 ** 31 - 1) | 1", "x = 2147483647");
         test("x = (2 ** 31) | 1", "x = -2147483647");
+
+        // https://github.com/oxc-project/oxc/issues/7944
+        test_same("(x - 1) & 1");
+        test_same("(y >> 3) & 7");
+        test("(y & 3) & 7", "y & 3");
+        test_same("(y | 3) & 7");
+        test("y | 3 & 7", "y | 3");
     }
 
     #[test]
@@ -1364,6 +1374,7 @@ mod test {
         test_same("z = x * y");
         test_same("x = y * 5");
         // test("x = y + (z * 24 * 60 * 60 * 1000)", "x = y + z * 864E5");
+        test("x = y + (z & 24 & 60 & 60 & 1000)", "x = y + (z & 8)");
     }
 
     #[test]
@@ -1393,6 +1404,52 @@ mod test {
         test("x = Infinity % 0", "x = NaN");
     }
 
+    #[test]
+    fn test_fold_left() {
+        test_same("(+x - 1) + 2"); // not yet
+        test("(+x & 1) & 2", "+x & 0");
+    }
+
+    #[test]
+    fn test_fold_left_child_op() {
+        test_same("x & infinity & 2"); // FIXME: want x & 0
+        test_same("x - infinity - 2"); // FIXME: want "x-infinity"
+        test_same("x - 1 + infinity");
+        test_same("x - 2 + 1");
+        test_same("x - 2 + 3");
+        test_same("1 + x - 2 + 1");
+        test_same("1 + x - 2 + 3");
+        test_same("1 + x - 2 + 3 - 1");
+        test_same("f(x)-0");
+        test_same("x-0-0"); // FIXME: want x - 0
+        test_same("x+2-2+2");
+        test_same("x+2-2+2-2");
+        test_same("x-2+2");
+        test_same("x-2+2-2");
+        test_same("x-2+2-2+2");
+
+        test_same("1+x-0-na_n");
+        test_same("1+f(x)-0-na_n");
+        test_same("1+x-0+na_n");
+        test_same("1+f(x)-0+na_n");
+
+        test_same("1+x+na_n"); // unfoldable
+        test_same("x+2-2"); // unfoldable
+        test_same("x+2"); // nothing to do
+        test_same("x-2"); // nothing to do
+    }
+
+    #[test]
+    fn test_associative_fold_constants_with_variables() {
+        // mul and add should not fold
+        test_same("alert(x * 12 * 20);");
+        test_same("alert(12 * x * 20);");
+        test_same("alert(x + 12 + 20);");
+        test_same("alert(12 + x + 20);");
+        test("alert(x & 12 & 20);", "alert(x & 4);");
+        test("alert(12 & x & 20);", "alert(x & 4);");
+    }
+
     #[test]
     fn test_to_number() {
         test("x = +''", "x = 0");

diff --git a/tasks/minsize/minsize.snap b/tasks/minsize/minsize.snap
@@ -5,23 +5,23 @@ Original   | minified   | minified   | gzip       | gzip       | Fixture
 
 173.90 kB  | 61.61 kB   | 59.82 kB   | 19.55 kB   | 19.33 kB   | moment.js 
 
-287.63 kB  | 92.60 kB   | 90.07 kB   | 32.26 kB   | 31.95 kB   | jquery.js 
+287.63 kB  | 92.61 kB   | 90.07 kB   | 32.27 kB   | 31.95 kB   | jquery.js 
 
 342.15 kB  | 121.79 kB  | 118.14 kB  | 44.59 kB   | 44.37 kB   | vue.js    
 
 544.10 kB  | 73.37 kB   | 72.48 kB   | 26.13 kB   | 26.20 kB   | lodash.js 
 
-555.77 kB  | 276.15 kB  | 270.13 kB  | 91.13 kB   | 90.80 kB   | d3.js     
+555.77 kB  | 276.22 kB  | 270.13 kB  | 91.15 kB   | 90.80 kB   | d3.js     
 
 1.01 MB    | 467.14 kB  | 458.89 kB  | 126.74 kB  | 126.71 kB  | bundle.min.js
 
-1.25 MB    | 662.53 kB  | 646.76 kB  | 163.97 kB  | 163.73 kB  | three.js  
+1.25 MB    | 662.68 kB  | 646.76 kB  | 164.00 kB  | 163.73 kB  | three.js  
 
-2.14 MB    | 740.87 kB  | 724.14 kB  | 181.46 kB  | 181.07 kB  | victory.js
+2.14 MB    | 740.94 kB  | 724.14 kB  | 181.49 kB  | 181.07 kB  | victory.js
 
-3.20 MB    | 1.02 MB    | 1.01 MB    | 332.10 kB  | 331.56 kB  | echarts.js
+3.20 MB    | 1.02 MB    | 1.01 MB    | 332.09 kB  | 331.56 kB  | echarts.js
 
 6.69 MB    | 2.39 MB    | 2.31 MB    | 496.17 kB  | 488.28 kB  | antd.js   
 
-10.95 MB   | 3.55 MB    | 3.49 MB    | 910.45 kB  | 915.50 kB  | typescript.js
+10.95 MB   | 3.55 MB    | 3.49 MB    | 910.48 kB  | 915.50 kB  | typescript.js