fix(es/minifier): minify.{keep_fnames,keep_classnames} should set both compress and mangle

crates/swc/src/config/mod.rs

@@ -415,6 +415,74 @@ impl Options {
             });
         }
 
+        if js_minify.is_some() && js_minify.as_ref().unwrap().keep_fnames {
+            js_minify = js_minify.map(|c| {
+                let compress = c
+                    .compress
+                    .unwrap_as_option(|default| match default {
+                        Some(true) => Some(Default::default()),
+                        _ => None,
+                    })
+                    .map(|mut c| {
+                        c.keep_fnames = true;
+                        c
+                    })
+                    .map(BoolOrDataConfig::from_obj)
+                    .unwrap_or_else(|| BoolOrDataConfig::from_bool(false));
+                let mangle = c
+                    .mangle
+                    .unwrap_as_option(|default| match default {
+                        Some(true) => Some(Default::default()),
+                        _ => None,
+                    })
+                    .map(|mut c| {
+                        c.keep_fn_names = true;
+                        c
+                    })
+                    .map(BoolOrDataConfig::from_obj)
+                    .unwrap_or_else(|| BoolOrDataConfig::from_bool(false));
+                JsMinifyOptions {
+                    compress,
+                    mangle,
+                    ..c
+                }
+            });
+        }
+
+        if js_minify.is_some() && js_minify.as_ref().unwrap().keep_classnames {
+            js_minify = js_minify.map(|c| {
+                let compress = c
+                    .compress
+                    .unwrap_as_option(|default| match default {
+                        Some(true) => Some(Default::default()),
+                        _ => None,
+                    })
+                    .map(|mut c| {
+                        c.keep_classnames = true;
+                        c
+                    })
+                    .map(BoolOrDataConfig::from_obj)
+                    .unwrap_or_else(|| BoolOrDataConfig::from_bool(false));
+                let mangle = c
+                    .mangle
+                    .unwrap_as_option(|default| match default {
+                        Some(true) => Some(Default::default()),
+                        _ => None,
+                    })
+                    .map(|mut c| {
+                        c.keep_class_names = true;
+                        c
+                    })
+                    .map(BoolOrDataConfig::from_obj)
+                    .unwrap_or_else(|| BoolOrDataConfig::from_bool(false));
+                JsMinifyOptions {
+                    compress,
+                    mangle,
+                    ..c
+                }
+            });
+        }
+
         let regenerator = transform.regenerator.clone();
 
         let preserve_comments = if preserve_all_comments {

crates/swc/src/lib.rs

@@ -1028,6 +1028,15 @@ impl Compiler {
                 }
             }
 
+            if opts.keep_fnames {
+                if let Some(opts) = &mut min_opts.compress {
+                    opts.keep_fnames = true;
+                }
+                if let Some(opts) = &mut min_opts.mangle {
+                    opts.keep_fn_names = true;
+                }
+            }
+
             let comments = SingleThreadedComments::default();
 
             let module = self

node-swc/__tests__/minify/issue_6996_test.mjs

@@ -1,7 +1,7 @@
 import swc from "../../..";
 
 it("should not throw when keep_fnames is on", async () => {
-    async function minify() {
+    async function transform() {
         const { code } = await swc.transform('function Foo() {}', {
             jsc: {
                 minify: {
@@ -11,5 +11,35 @@ it("should not throw when keep_fnames is on", async () => {
         });
         return code;
     }
-    await expect(minify()).resolves.toEqual('function Foo() {}\n');
+    // should not reject with unknown field `keep_fnames`
+    await expect(transform()).resolves.toEqual('function Foo() {}\n');
+});
+
+it("should pass on keep_fnames to minify.{mangle,compress}", async () => {
+    const { code } = await swc.transform('export default function Foo() {}', {
+        jsc: {
+            minify: {
+                compress: {},
+                mangle: {},
+                keep_fnames: true,
+            },
+        },
+        minify: true,
+    });
+    expect(code).toEqual('export default function Foo(){}');
+});
+
+it("should pass on keep_classnames to minify.{mangle,compress}", async () => {
+    const { code } = await swc.transform('export default class Foo {}', {
+        jsc: {
+            minify: {
+                compress: {},
+                mangle: {},
+                keep_classnames: true,
+            },
+            target: 'esnext',
+        },
+        minify: true,
+    });
+    expect(code).toEqual('export default class Foo{}');
 });