added integration test

moved test image files to res folder
fixed bugs in image loader

.gitignore

@@ -3,3 +3,4 @@
 .DS_Store
 .idea
 /.vscode
+*.json

src/image_loader/mod.rs

@@ -267,7 +267,7 @@ mod test {
 
     #[test]
     fn test_image_loader() {
-        let path = Path::new("test_img/red_image.png");
+        let path = Path::new("res/test_img/red_image.png");
         let test = image_loader(path);
 
         let image = Image::new(
@@ -300,7 +300,7 @@ mod test {
     #[test]
     #[should_panic]
     fn test_wrong_img() {
-        let path = Path::new("test_img/wrong pixel count.png");
+        let path = Path::new("res/test_img/wrong pixel count.png");
         let test = image_loader(path);
 
         let image = Image::new(

src/search_index/mod.rs

@@ -313,6 +313,11 @@ impl Database {
             threadpool: ThreadPool::new(),
         }
     }
+
+    pub fn write_to_file(&self, path: &Path) {
+        let filestring = serde_json::to_string(&self.images).expect("unable to serialize the file");
+        fs::write(path, filestring).expect("unable to write the file");
+    }
 }
 
 ///IndexedImages stores the images of the Database and is serializable

tests/integration_test.rs

@@ -0,0 +1,82 @@
+use std::{path::Path, sync::Arc};
+
+use imsearch::{
+    image::Image,
+    search_index::{Database, FeatureGenerator, FeatureResult},
+};
+
+fn average_brightness(image: Arc<Image<f32>>) -> (String, FeatureResult) {
+    let bright = image
+        .pixels()
+        .iter()
+        .map(|(r, g, b, _)| (r + g + b) / 3.0 / 255.0)
+        .sum::<f32>()
+        / image.pixels().len() as f32;
+
+    (
+        String::from("average_brightness"),
+        FeatureResult::Percent(bright),
+    )
+}
+
+#[test]
+fn test_database_basic() {
+    let files: Vec<std::path::PathBuf> = std::fs::read_dir("res/integration/")
+        .unwrap()
+        .map(|f| f.unwrap().path())
+        .collect();
+
+    let feats: Vec<FeatureGenerator> = vec![average_brightness];
+
+    let db = Database::new(&files, feats).unwrap();
+
+    for results in db
+        .search(
+            std::path::Path::new("res/integration/gray_image.png"),
+            average_brightness,
+        )
+        .unwrap()
+    {
+        println!(
+            "path: {} similarity: {}",
+            results.0.as_os_str().to_str().unwrap(),
+            results.1
+        );
+    }
+}
+
+#[test]
+fn test_database_files() {
+    let json = Path::new("db.json");
+
+    {
+        let files: Vec<std::path::PathBuf> = std::fs::read_dir("res/integration/")
+            .unwrap()
+            .map(|f| f.unwrap().path())
+            .collect();
+
+        let feats: Vec<FeatureGenerator> = vec![average_brightness];
+
+        let db = Database::new(&files, feats).unwrap();
+
+        db.write_to_file(json);
+    }
+
+    {
+        let db = Database::from_file(json);
+
+        for results in db
+            .search(
+                std::path::Path::new("res/integration/gray_image.png"),
+                average_brightness,
+            )
+            .unwrap()
+        {
+            println!(
+                "path: {} similarity: {}",
+                results.0.as_os_str().to_str().unwrap(),
+                results.1
+            );
+        }
+    }
+}