automatically create gitbutler-ui/build

.github/actions/init-env-rust/action.yaml

@@ -10,10 +10,6 @@ runs:
         prefix-key: gitbutler-client
         shared-key: rust
 
-    - name: Placeholder for ui assets
-      shell: bash
-      run: mkdir gitbutler-ui/build
-
     - name: Check versions
       shell: bash
       run: |

gitbutler-app/build.rs

@@ -1,3 +1,23 @@
 fn main() {
+    // Make the UI build directory if it doesn't already exist.
+    // We do this here because the tauri context macro expects it to
+    // exist at build time, and it's otherwise manually required to create
+    // it before building.
+    let manifest_dir = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    assert_eq!(manifest_dir.file_name().unwrap(), "gitbutler-app");
+    let build_dir = manifest_dir.parent().unwrap().join("gitbutler-ui/build");
+    if !build_dir.exists() {
+        // NOTE(qix-): Do not use `create_dir_all` here - the parent directory
+        // NOTE(qix-): already exists, and we want to fail if not (for some reason).
+        #[allow(clippy::expect_fun_call, clippy::create_dir)]
+        std::fs::create_dir(&build_dir).expect(
+            format!(
+                "failed to create gitbutler-ui build directory: {:?}",
+                build_dir
+            )
+            .as_str(),
+        );
+    }
+
     tauri_build::build();
 }