analysis: keep-lock mixin classes and plugins from mixins.json configs

crates/noxis-analysis/tests/mixins.rs

@@ -0,0 +1,75 @@
+//! Mixin keep: classes listed in `*.mixins.json` (and the plugin) stay.
+//!
+//! The Mixin framework resolves mixin classes and their members by name at
+//! runtime, so renaming them breaks the mod at startup. Entries use simple
+//! names relative to the `package` field, which generic text patching can
+//! never see - locking is the only sound answer.
+
+#![allow(clippy::expect_used, clippy::unwrap_used)]
+
+use noxis_analysis::Analysis;
+use noxis_classfile::{ClassBuilder, Program, Resource, Version};
+use noxis_core::Config;
+
+const MIXINS: &str = r#"{
+  "package": "demo.mixin",
+  "plugin": "demo.mixin.Plugin",
+  "mixins": ["TargetMixin", "other.Helper"],
+  "client": ["ClientMixin"]
+}"#;
+
+const FABRIC: &str = r#"{
+  "id": "demo",
+  "mixins": ["demo.mixins.json"]
+}"#;
+
+fn sample() -> Program {
+    let mut program = Program {
+        classes: vec![
+            ClassBuilder::new("demo/mixin/TargetMixin", Some("java/lang/Object"))
+                .version(Version::JAVA_21)
+                .build(),
+            ClassBuilder::new("demo/mixin/other/Helper", Some("java/lang/Object"))
+                .version(Version::JAVA_21)
+                .build(),
+            ClassBuilder::new("demo/mixin/ClientMixin", Some("java/lang/Object"))
+                .version(Version::JAVA_21)
+                .build(),
+            ClassBuilder::new("demo/mixin/Plugin", Some("java/lang/Object"))
+                .version(Version::JAVA_21)
+                .build(),
+            ClassBuilder::new("demo/App", Some("java/lang/Object"))
+                .version(Version::JAVA_21)
+                .build(),
+        ],
+        resources: Vec::new(),
+    };
+    program.resources.push(Resource {
+        path: "demo.mixins.json".into(),
+        data: MIXINS.as_bytes().to_vec(),
+    });
+    program.resources.push(Resource {
+        path: "fabric.mod.json".into(),
+        data: FABRIC.as_bytes().to_vec(),
+    });
+    program
+}
+
+#[test]
+fn mixin_classes_and_plugin_stay() {
+    let program = sample();
+    let analysis = Analysis::run(&program, &Config::default()).expect("analysis");
+
+    for kept in [
+        "demo/mixin/TargetMixin",
+        "demo/mixin/other/Helper",
+        "demo/mixin/ClientMixin",
+        "demo/mixin/Plugin",
+    ] {
+        assert!(analysis.is_locked(kept), "{kept} must survive renaming");
+    }
+    assert!(
+        !analysis.is_locked("demo/App"),
+        "ordinary classes must still rename"
+    );
+}