From fb3749aff692a7a8225dff00a4516b48a76866b6 Mon Sep 17 00:00:00 2001
From: morluto <76467478+morluto@users.noreply.github.com>
Date: Wed, 7 Oct 2026 23:00:22 +0800
Subject: [PATCH] fix(android): align runtime suffix inference (#977)

---
 src/domain/android/androidApplication.ts      | 11 ++++-
 tests/composition/android/application.test.ts | 44 +++++++++++++++++++
 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/src/domain/android/androidApplication.ts b/src/domain/android/androidApplication.ts
index 0a48a8a98..55718a664 100644
--- a/src/domain/android/androidApplication.ts
+++ b/src/domain/android/androidApplication.ts
@@ -118,6 +118,7 @@ export const projectAndroidApplication = (
       ? ["Source inventory pages are incomplete; absence is unknown."]
       : []),
     "Manifest, resource, signing, and bytecode semantics require a dedicated Android provider; this projection reports exact inventory paths and hashes only.",
+    "Runtime families are inferred from inventory formats and paths; filename suffixes do not establish valid DEX or JVM class bytes.",
     "Bridge candidates are path-based hypotheses, not decoded JNI declarations or observed runtime calls.",
   ];
   const withoutId = {
@@ -176,11 +177,17 @@ const runtimeFamilies = (all: readonly Component[]) => {
   const families = new Set<
     AndroidApplicationProjectionResult["runtime_families"][number]
   >();
-  if (all.some(({ path, format }) => format === "dex" || path.endsWith(".dex")))
+  if (
+    all.some(
+      ({ path, format }) =>
+        format === "dex" || path.toLowerCase().endsWith(".dex"),
+    )
+  )
     families.add("dalvik-art");
   if (
     all.some(
-      ({ path, format }) => format === "jvm-class" || path.endsWith(".class"),
+      ({ path, format }) =>
+        format === "jvm-class" || path.toLowerCase().endsWith(".class"),
     )
   )
     families.add("java-kotlin");
diff --git a/tests/composition/android/application.test.ts b/tests/composition/android/application.test.ts
index fe8def8ad..ad7ff2b94 100644
--- a/tests/composition/android/application.test.ts
+++ b/tests/composition/android/application.test.ts
@@ -99,6 +99,50 @@ describe("Android application projection", () => {
     });
   });
 
+  it("keeps uppercase path-derived bytecode families distinct from byte validity", async () => {
+    const root = await createTestTempDirectory("rea-android-suffixes-");
+    const path = join(root, "Suffixes.apk");
+    const writer = new ZipWriter(new Uint8ArrayWriter());
+    for (const entry of [
+      "classes.DEX",
+      "extra.dex",
+      "Main.CLASS",
+      "Other.class",
+    ])
+      await writer.add(entry, new TextReader("unrecognized bytes"));
+    await writeFile(path, await writer.close());
+
+    const inventory = parseEvidence(
+      await runProviderAnalysis(path, "inventory_artifact", {}),
+    );
+    const result = projectAndroidApplicationEvidence({
+      inventory_evidence: [inventory],
+    });
+    const projection = androidApplicationProjectionResultSchema.parse(
+      requireSuccessfulProjection(result).normalized_result,
+    );
+
+    expect(projection.components.dex.map(({ path }) => path).sort()).toEqual([
+      "classes.DEX",
+      "extra.dex",
+    ]);
+    expect(
+      projection.components.jvm_classes.map(({ path }) => path).sort(),
+    ).toEqual(["Main.CLASS", "Other.class"]);
+    expect(
+      projection.components.dex.every(({ format }) => format === "file"),
+    ).toBe(true);
+    expect(
+      projection.components.jvm_classes.every(
+        ({ format }) => format === "file",
+      ),
+    ).toBe(true);
+    expect(projection.runtime_families).toEqual(["dalvik-art", "java-kotlin"]);
+    expect(projection.limitations).toContain(
+      "Runtime families are inferred from inventory formats and paths; filename suffixes do not establish valid DEX or JVM class bytes.",
+    );
+  });
+
   it("returns every component and bridge candidate from the inventory", async () => {
     const root = await createTestTempDirectory("rea-android-complete-");
     const path = join(root, "Fixture.apk");