feat(minifier): merge similar if stmts

oxc-project · Jan 15, 2025 · 72fa9df · 72fa9df
1 parent aa9d7e4
commit 72fa9df
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Showing 3 changed files with 62 additions and 23 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
@@ -215,19 +215,53 @@ impl<'a> PeepholeMinimizeConditions {
 
     fn try_replace_if(&mut self, stmts: &mut Vec<'a, Statement<'a>>, ctx: &mut TraverseCtx<'a>) {
         for i in 0..stmts.len() {
-            let Statement::IfStatement(if_stmt) = &stmts[i] else {
+            let (current_node, next_node) = {
+                if i == stmts.len() - 1 {
+                    (stmts.get_mut(i).unwrap(), None)
+                } else {
+                    let (left, right) = stmts.split_at_mut(i + 1);
+                    (left.last_mut().unwrap(), right.first_mut())
+                }
+            };
+
+            let Statement::IfStatement(if_stmt) = &current_node else {
                 continue;
             };
+
             let then_branch = &if_stmt.consequent;
             let else_branch = &if_stmt.alternate;
-            let next_node = stmts.get(i + 1);
 
-            if next_node.is_some_and(|s| matches!(s, Statement::IfStatement(_)))
+            if next_node.as_ref().is_some_and(|s| matches!(s, Statement::IfStatement(_)))
                 && else_branch.is_none()
-                && Self::is_return_block(then_branch)
+                && Self::statement_must_exit_parent(then_branch)
             {
-                /* TODO */
-            } else if next_node.is_some_and(Self::is_return_expression)
+                // let next_node = next_node.unwrap();
+                // // `if (x) return; if (y) return;` -> `if (x || y) return;`
+                // let Statement::IfStatement(next_if) = next_node else { unreachable!() };
+
+                // if next_if.alternate.is_none() && next_if.consequent.content_eq(&if_stmt.consequent)
+                // {
+                //     let Statement::IfStatement(mut if_stmt) = ctx.ast.move_statement(current_node)
+                //     else {
+                //         unreachable!()
+                //     };
+
+                //     let Statement::IfStatement(mut next) = ctx.ast.move_statement(next_node) else {
+                //         unreachable!()
+                //     };
+                //     let test = ctx.ast.expression_logical(
+                //         next.test.span(),
+                //         ctx.ast.move_expression(&mut if_stmt.test),
+                //         LogicalOperator::Or,
+                //         ctx.ast.move_expression(&mut next.test),
+                //     );
+                //     if_stmt.test = test;
+                //     stmts[i] = Statement::IfStatement(if_stmt);
+                //     self.changed = true;
+                // }
+
+                // TODO: `if (x) return 1; if (y) foo() else return 1;` -> `if (!x&&y) foo() else return 1;`
+            } else if next_node.as_deref().is_some_and(Self::is_return_expression)
                 && else_branch.is_none()
                 && Self::is_return_block(then_branch)
             {
@@ -248,6 +282,7 @@ impl<'a> PeepholeMinimizeConditions {
                 self.changed = true;
                 break;
             } else if else_branch.is_some() && Self::statement_must_exit_parent(then_branch) {
+                // `if (x) return; else return 1` -> `return x ? void 0 : 1`
                 let Statement::IfStatement(if_stmt) = &mut stmts[i] else {
                     unreachable!();
                 };
@@ -951,12 +986,16 @@ mod test {
     }
 
     #[test]
-    #[ignore]
-    fn test_combine_ifs1() {
+    fn test_combine_ifs() {
         fold(
             "function f() {if (x) return 1; if (y) return 1}",
             "function f() {if (x||y) return 1;}",
         );
+    }
+
+    #[test]
+    #[ignore]
+    fn test_combine_ifs1() {
         fold(
             "function f() {if (x) return 1; if (y) foo(); else return 1}",
             "function f() {if ((!x)&&y) foo(); else return 1;}",
@@ -966,8 +1005,10 @@ mod test {
     #[test]
     #[ignore]
     fn test_combine_ifs2() {
-        // combinable but not yet done
-        fold_same("function f() {if (x) throw 1; if (y) throw 1}");
+        fold(
+            "function f() {if (x) throw 1; if (y) throw 1}",
+            "function f() {if (x || y) throw 1;}",
+        );
         // Can't combine, side-effect
         fold("function f(){ if (x) g(); if (y) g() }", "function f(){ x&&g(); y&&g() }");
         fold("function f(){ if (x) g?.(); if (y) g?.() }", "function f(){ x&&g?.(); y&&g?.() }");

diff --git a/crates/oxc_minifier/tests/ast_passes/mod.rs b/crates/oxc_minifier/tests/ast_passes/mod.rs
@@ -149,9 +149,7 @@ fn cjs() {
         });"#,
         "
         Object.keys(_index6).forEach(function(key) {
-        if (key === 'default' || key === '__esModule') return;
-        if (Object.prototype.hasOwnProperty.call(_exportNames, key)) return;
-        if (key in exports && exports[key] === _index6[key]) return;
+        if (key === 'default' || key === '__esModule' || Object.prototype.hasOwnProperty.call(_exportNames, key) || key in exports && exports[key] === _index6[key]) return;
         Object.defineProperty(exports, key, {
                 enumerable: true,
                 get: function() {

diff --git a/tasks/minsize/minsize.snap b/tasks/minsize/minsize.snap
@@ -3,25 +3,25 @@ Original   | minified   | minified   | gzip       | gzip       | Fixture
 -------------------------------------------------------------------------------------
 72.14 kB   | 23.70 kB   | 23.70 kB   | 8.60 kB    | 8.54 kB    | react.development.js
 
-173.90 kB  | 59.79 kB   | 59.82 kB   | 19.41 kB   | 19.33 kB   | moment.js 
+173.90 kB  | 59.68 kB   | 59.82 kB   | 19.40 kB   | 19.33 kB   | moment.js 
 
-287.63 kB  | 90.08 kB   | 90.07 kB   | 32.03 kB   | 31.95 kB   | jquery.js 
+287.63 kB  | 90.06 kB   | 90.07 kB   | 32.03 kB   | 31.95 kB   | jquery.js 
 
-342.15 kB  | 118.11 kB  | 118.14 kB  | 44.44 kB   | 44.37 kB   | vue.js    
+342.15 kB  | 118.07 kB  | 118.14 kB  | 44.44 kB   | 44.37 kB   | vue.js    
 
 544.10 kB  | 71.76 kB   | 72.48 kB   | 26.15 kB   | 26.20 kB   | lodash.js 
 
-555.77 kB  | 273.15 kB  | 270.13 kB  | 90.92 kB   | 90.80 kB   | d3.js     
+555.77 kB  | 273.14 kB  | 270.13 kB  | 90.91 kB   | 90.80 kB   | d3.js     
 
-1.01 MB    | 460.17 kB  | 458.89 kB  | 126.76 kB  | 126.71 kB  | bundle.min.js
+1.01 MB    | 459.65 kB  | 458.89 kB  | 126.75 kB  | 126.71 kB  | bundle.min.js
 
-1.25 MB    | 652.84 kB  | 646.76 kB  | 163.54 kB  | 163.73 kB  | three.js  
+1.25 MB    | 652.73 kB  | 646.76 kB  | 163.55 kB  | 163.73 kB  | three.js  
 
-2.14 MB    | 725.68 kB  | 724.14 kB  | 180.07 kB  | 181.07 kB  | victory.js
+2.14 MB    | 725.66 kB  | 724.14 kB  | 180.08 kB  | 181.07 kB  | victory.js
 
-3.20 MB    | 1.01 MB    | 1.01 MB    | 331.79 kB  | 331.56 kB  | echarts.js
+3.20 MB    | 1.01 MB    | 1.01 MB    | 331.78 kB  | 331.56 kB  | echarts.js
 
-6.69 MB    | 2.32 MB    | 2.31 MB    | 492.64 kB  | 488.28 kB  | antd.js   
+6.69 MB    | 2.32 MB    | 2.31 MB    | 492.61 kB  | 488.28 kB  | antd.js   
 
-10.95 MB   | 3.49 MB    | 3.49 MB    | 907.42 kB  | 915.50 kB  | typescript.js
+10.95 MB   | 3.49 MB    | 3.49 MB    | 907.29 kB  | 915.50 kB  | typescript.js