Add OfflineDownload.NoFreezingOnCachedTilesAndNewStyle unit test

test/src/mbgl/test/stub_file_source.cpp

@@ -70,6 +70,15 @@ void StubFileSource::remove(AsyncRequest* req) {
     }
 }
 
+void StubFileSource::setProperty(const std::string& key, const mapbox::base::Value& value) {
+    properties[key] = value;
+}
+
+mapbox::base::Value StubFileSource::getProperty(const std::string& key) const {
+    auto it = properties.find(key);
+    return (it != properties.end()) ? it->second : mapbox::base::Value();
+}
+
 optional<Response> StubFileSource::defaultResponse(const Resource& resource) {
     switch (resource.kind) {
     case Resource::Kind::Style:

test/src/mbgl/test/stub_file_source.hpp

@@ -5,6 +5,7 @@
 #include <mbgl/storage/resource.hpp>
 #include <mbgl/util/timer.hpp>
 
+#include <map>
 #include <unordered_map>
 
 namespace mbgl {
@@ -22,6 +23,8 @@ public:
     std::unique_ptr<AsyncRequest> request(const Resource&, Callback) override;
     bool canRequest(const Resource&) const override { return true; }
     void remove(AsyncRequest*);
+    void setProperty(const std::string&, const mapbox::base::Value&) override;
+    mapbox::base::Value getProperty(const std::string&) const override;
 
     using ResponseFunction = std::function<optional<Response> (const Resource&)>;
 
@@ -48,6 +51,7 @@ private:
     std::unordered_map<AsyncRequest*, std::tuple<Resource, ResponseFunction, Callback>> pending;
     ResponseType type;
     util::Timer timer;
+    std::map<std::string, mapbox::base::Value> properties;
 };
 
 } // namespace mbgl

test/storage/offline_download.test.cpp

@@ -1026,3 +1026,39 @@ TEST(OfflineDownload, InterruptAndResume) {
     download.setState(OfflineRegionDownloadState::Active);
     test.loop.run();
 }
+
+TEST(OfflineDownload, NoFreezingOnCachedTilesAndNewStyle) {
+    OfflineTest test;
+    auto region = test.createRegion();
+    ASSERT_TRUE(region);
+    OfflineDownload download(region->getID(),
+                             OfflineTilePyramidRegionDefinition(
+                                 "http://127.0.0.1:3000/style.json", LatLngBounds::world(), 1.0, 1.0, 1.0, true),
+                             test.db,
+                             test.fileSource);
+
+    test.fileSource.setProperty(MAX_CONCURRENT_REQUESTS_KEY, 2u);
+    test.fileSource.styleResponse = [&](const Resource&) { return test.response("inline_source.style.json"); };
+    // Number of resources must exceed MAX_CONCURRENT_REQUESTS_KEY
+    test.db.put(Resource::tile("http://127.0.0.1:3000/{z}-{x}-{y}.vector.pbf", 1, 0, 0, 1, Tileset::Scheme::XYZ),
+                test.response("0-0-0.vector.pbf"));
+    test.db.put(Resource::tile("http://127.0.0.1:3000/{z}-{x}-{y}.vector.pbf", 1, 0, 1, 1, Tileset::Scheme::XYZ),
+                test.response("0-0-0.vector.pbf"));
+    test.db.put(Resource::tile("http://127.0.0.1:3000/{z}-{x}-{y}.vector.pbf", 1, 1, 0, 1, Tileset::Scheme::XYZ),
+                test.response("0-0-0.vector.pbf"));
+    test.db.put(Resource::tile("http://127.0.0.1:3000/{z}-{x}-{y}.vector.pbf", 1, 1, 1, 1, Tileset::Scheme::XYZ),
+                test.response("0-0-0.vector.pbf"));
+
+    auto observer = std::make_unique<MockObserver>();
+    observer->statusChangedFn = [&](OfflineRegionStatus status) {
+        if (status.complete()) {
+            test.loop.stop();
+        }
+    };
+
+    download.setObserver(std::move(observer));
+    download.setState(OfflineRegionDownloadState::Active);
+
+    test.loop.run();
+    // Passes if does not freeze.
+}