feat(es): Use minify.format.ascii_only if output.charset is not s…

…pecified (#7258)

**Related issue:**

 - Closes #7240.

crates/swc/src/config/mod.rs

@@ -577,6 +577,14 @@ impl Options {
             _ => TsImportExportAssignConfig::Classic,
         };
 
+        let charset = cfg.jsc.output.charset.or_else(|| {
+            if js_minify.as_ref()?.format.ascii_only {
+                Some(OutputCharset::Ascii)
+            } else {
+                None
+            }
+        });
+
         let pass = PassBuilder::new(
             cm,
             handler,
@@ -782,7 +790,7 @@ impl Options {
             comments: comments.cloned(),
             preserve_comments,
             emit_source_map_columns: cfg.emit_source_map_columns.into_bool(),
-            output: cfg.jsc.output,
+            output: JscOutputConfig { charset },
         })
     }
 }

crates/swc/tests/fixture/issues-7xxx/7240/input/.swcrc

@@ -0,0 +1,33 @@
+{
+    "jsc": {
+        "parser": {
+            "syntax": "ecmascript",
+            "jsx": false
+        },
+        "target": "es5",
+        "loose": true,
+        "minify": {
+            "compress": {
+                "dead_code": true,
+                "drop_console": true,
+                "drop_debugger": true,
+                "passes": 3
+            },
+            "format": {
+                "asciiOnly": true
+            },
+            "mangle": {
+                "toplevel": false,
+                "keep_classnames": false,
+                "keep_fnames": false,
+                "keep_private_props": false,
+                "ie8": false,
+                "safari10": false
+            }
+        }
+    },
+    "module": {
+        "type": "commonjs"
+    },
+    "isModule": true
+}

crates/swc/tests/fixture/issues-7xxx/7240/input/index.js

@@ -0,0 +1,5 @@
+export default {
+    \u3131: '\u11B0',
+    '\u3141': '\u11B1',
+    ['\u3142']: '\u11B2',
+}

crates/swc/tests/fixture/issues-7xxx/7240/output/index.js

@@ -0,0 +1,13 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", {
+    value: !0
+}), Object.defineProperty(exports, "default", {
+    enumerable: !0,
+    get: function() {
+        return _default;
+    }
+});
+var _obj, _default = ((_obj = {
+    \u3131: "\u11B0",
+    \u3141: "\u11B1"
+})["\u3142"] = "\u11B2", _obj);