Build Android example as part of CI.

.github/workflows/test.yml

@@ -60,3 +60,24 @@ jobs:
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           args: --all-features --target wasm32-unknown-unknown
+
+  check_android:
+    name: Check Android
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: Swatinem/rust-cache@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          components: rustfmt, clippy
+          override: true
+      - uses: actions-rs/install@v0.1
+        with:
+          crate: cargo-make
+          use-tool-cache: true
+      - uses: actions-rs/cargo@v1
+        with:
+          command: make
+          args: build-android-example

Makefile.toml

@@ -1,4 +1,10 @@
-[tasks.run-android]
+[tasks.build-android-example]
+script = [
+    "cd examples/android",
+    "./gradlew assembleDebug",
+]
+
+[tasks.run-android-example]
 script = [
     "cd examples/android",
     "./gradlew runDebug",

examples/android/src/lib.rs

@@ -1,5 +1,8 @@
 use tts::*;
 
+// The `loop {}` below only simulates an app loop.
+// Without it, the `TTS` instance gets dropped before callbacks can run.
+#[allow(unreachable_code)]
 fn run() -> Result<(), Error> {
     let mut tts = TTS::default()?;
     let Features {