look for database in default directory, download it during ci tests

.forgejo/workflows/build.yaml

@@ -19,7 +19,7 @@ jobs:
       - name: Build project
         run: zig build --summary all
       - name: Run tests
-        run: zig build test --summary all
+        run: zig build test -Ddownload-geoip --summary all
       - name: Package
         run: zig build -Dtarget="$BUILD_TARGET" -Doptimize="$BUILD_OPTIMIZATION"
       - name: Upload

src/config.zig

@@ -5,8 +5,18 @@ pub const Config = struct {
     listen_port: u16,
     cache_size: usize,
     cache_dir: []const u8,
+
+    /// GeoLite2 is used for GeoIP (IP -> geographic location)
+    /// IP2Location is a fallback if IP is not found in this db
     geolite_path: []const u8,
+
+    /// Geocache file stores location lookups
+    /// (e.g. "Portland -> 45.52345°N, -122.67621° W). When not found in cache,
+    /// a web service from Nominatum (https://nominatim.org/) is used
     geocache_file: ?[]const u8,
+
+    /// If provided, when GeoLite2 is missing data, https://www.ip2location.com/
+    /// can be used. This will also be cached in the cached file
     ip2location_api_key: ?[]const u8,
     ip2location_cache_file: []const u8,
 

src/location/GeoIp.zig

@@ -138,8 +138,12 @@ test "GeoIP init with invalid path fails" {
 }
 
 test "isUSIP detects US IPs" {
+    const allocator = std.testing.allocator;
+    const Config = @import("../config.zig").Config;
+    const config = try Config.load(allocator);
+    defer config.deinit(allocator);
     const build_options = @import("build_options");
-    const db_path = "./GeoLite2-City.mmdb";
+    const db_path = config.geolite_path;
 
     if (build_options.download_geoip) {
         const GeoLite2 = @import("GeoLite2.zig");