feat(minifier): minimize logical exprs

oxc-project · Jan 1, 2025 · 18fd030 · 18fd030
1 parent 4c2059a
commit 18fd030
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Showing 2 changed files with 62 additions and 11 deletions.
diff --git a/crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs b/crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs
@@ -57,6 +57,9 @@ impl<'a> Traverse<'a> for PeepholeMinimizeConditions {
     fn exit_expression(&mut self, expr: &mut Expression<'a>, ctx: &mut TraverseCtx<'a>) {
         if let Some(folded_expr) = match expr {
             Expression::UnaryExpression(e) => Self::try_minimize_not(e, ctx),
+            Expression::LogicalExpression(logical_expr) => {
+                Self::try_minimize_logical(logical_expr, ctx)
+            }
             Expression::ConditionalExpression(conditional_expr) => {
                 Self::try_minimize_conditional(conditional_expr, ctx)
             }
@@ -257,6 +260,49 @@ impl<'a> PeepholeMinimizeConditions {
         }
     }
 
+    fn try_minimize_logical(
+        expr: &mut LogicalExpression<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) -> Option<Expression<'a>> {
+        // `a && true` -> `a`
+        // `a && false` -> `false`
+        if expr.operator == LogicalOperator::And {
+            if let (
+                Expression::Identifier(test_ident),
+                Expression::BooleanLiteral(consequent_lit),
+            ) = (&expr.left, &expr.right)
+            {
+                if consequent_lit.value {
+                    return Some(ctx.ast.move_expression(&mut expr.left));
+                }
+                if ctx.scopes().find_binding(ctx.current_scope_id(), &test_ident.name).is_some() {
+                    return Some(ctx.ast.expression_boolean_literal(expr.span, false));
+                }
+                return None;
+            }
+        }
+
+        // `a || true` -> `true`
+        // `a || false` -> `a`
+        if expr.operator == LogicalOperator::Or {
+            if let (
+                Expression::Identifier(test_ident),
+                Expression::BooleanLiteral(consequent_lit),
+            ) = (&expr.left, &expr.right)
+            {
+                if ctx.scopes().find_binding(ctx.current_scope_id(), &test_ident.name).is_some() {
+                    if !consequent_lit.value {
+                        return Some(ctx.ast.move_expression(&mut expr.left));
+                    }
+                    return Some(ctx.ast.expression_boolean_literal(expr.span, true));
+                }
+                return None;
+            }
+        }
+
+        None
+    }
+
     fn try_minimize_conditional(
         expr: &mut ConditionalExpression<'a>,
         ctx: &mut TraverseCtx<'a>,
@@ -591,14 +637,19 @@ mod test {
     #[test]
     #[ignore]
     fn test_minimize_expr_condition() {
-        fold("(x ? true : false) && y()", "x&&y()");
-        fold("(x ? false : true) && y()", "(!x)&&y()");
-        fold("(x ? true : y) && y()", "(x || y)&&y()");
-        fold("(x ? y : false) && y()", "(x && y)&&y()");
+        fold("(x ? true : false) && y()", "!!x && y()");
+        fold("(x ? false : true) && y()", "!x && y()");
+        fold("(x ? true : y) && y()", "(x || y) && y()");
+        fold("(x ? y : false) && y()", "(x && y) && y()");
+        fold("var x; (x && true) && y()", "var x; x && y()");
+        fold("var x; (x && false) && y()", "var x; false && y()");
         fold("(x && true) && y()", "x && y()");
-        fold("(x && false) && y()", "0&&y()");
-        fold("(x || true) && y()", "1&&y()");
-        fold("(x || false) && y()", "x&&y()");
+        fold("(x && false) && y()", "x && false && y()");
+        fold("var x; (x || true) && y()", "var x; true && y()");
+        fold("var x; (x || false) && y()", "var x; x && y()");
+
+        fold_same("(x || true) && y()");
+        fold("(x || false) && y()", "x && y()");
     }
 
     #[test]

diff --git a/tasks/minsize/minsize.snap b/tasks/minsize/minsize.snap
@@ -17,11 +17,11 @@ Original   | minified   | minified   | gzip       | gzip       | Fixture
 
 1.25 MB    | 653.18 kB  | 646.76 kB  | 163.57 kB  | 163.73 kB  | three.js  
 
-2.14 MB    | 726.72 kB  | 724.14 kB  | 180.25 kB  | 181.07 kB  | victory.js
+2.14 MB    | 726.71 kB  | 724.14 kB  | 180.25 kB  | 181.07 kB  | victory.js
 
-3.20 MB    | 1.01 MB    | 1.01 MB    | 332.13 kB  | 331.56 kB  | echarts.js
+3.20 MB    | 1.01 MB    | 1.01 MB    | 332.12 kB  | 331.56 kB  | echarts.js
 
-6.69 MB    | 2.32 MB    | 2.31 MB    | 493.04 kB  | 488.28 kB  | antd.js   
+6.69 MB    | 2.32 MB    | 2.31 MB    | 493.02 kB  | 488.28 kB  | antd.js   
 
-10.95 MB   | 3.51 MB    | 3.49 MB    | 910.11 kB  | 915.50 kB  | typescript.js
+10.95 MB   | 3.51 MB    | 3.49 MB    | 910.08 kB  | 915.50 kB  | typescript.js