bug fix : correct file extension derivation

internal/model/file_extension_test.go

@@ -0,0 +1,48 @@
+package model
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFileExtensionFromPath(t *testing.T) {
+	t.Parallel()
+
+	type parseTest struct {
+		inputString string
+		expectedExt string
+	}
+
+	parseTests := []parseTest{
+		{
+			inputString: "short film.mkv",
+			expectedExt: "mkv",
+		},
+		{
+			inputString: "short film.mkv.mk2",
+			expectedExt: "mk2",
+		},
+		{
+			inputString: "short film....mkv",
+			expectedExt: "mkv",
+		},
+		{
+			inputString: ".mkv",
+			expectedExt: "",
+		},
+		{
+			inputString: "short film.",
+			expectedExt: "",
+		},
+	}
+
+	for _, test := range parseTests {
+		t.Run(test.inputString, func(t *testing.T) {
+			t.Parallel()
+
+			actualOutput := FileExtensionFromPath(test.inputString)
+			assert.Equal(t, test.expectedExt, actualOutput.String)
+		})
+	}
+}

internal/model/torrent_files.go

@@ -30,7 +30,7 @@ func (f TorrentFile) BaseName() string {
 	return basePathParts[len(basePathParts)-1]
 }
 
-var fileExtensionRegex = regexp.MustCompile(`[^/.]\.([a-z0-9]+)$`)
+var fileExtensionRegex = regexp.MustCompile(`.\.([a-z0-9]+)$`)
 
 func FileExtensionFromPath(path string) NullString {
 	match := fileExtensionRegex.FindStringSubmatch(strings.ToLower(path))

migrations/00021_extension_default.sql

@@ -0,0 +1,29 @@
+-- +goose Up
+-- +goose StatementBegin
+
+alter table "torrents" drop column "extension";
+alter table "torrents" add column "extension" text generated always as (case
+  when files_status = 'single'::"FilesStatus"
+    then substring(lower(name) from '.\.([a-z0-9]+)$') end) stored;
+create index on torrents (extension);
+alter table "torrent_files" drop column "extension";
+alter table "torrent_files" add column "extension" text generated always as 
+    (substring(lower(path) from '.\.([a-z0-9]+)$')) stored;
+create index on torrent_files (extension);
+
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+
+alter table "torrents" drop column "extension";
+alter table "torrents" add column "extension" text generated always as (case
+  when files_status = 'single'::"FilesStatus"
+    then substring(lower(name) from '[^/.]\.([a-z0-9]+)$') end) stored;
+create index on torrents (extension);
+alter table "torrent_files" drop column "extension";
+alter table "torrent_files" add column "extension" text generated always as 
+    (substring(lower(path) from '[^/.]\.([a-z0-9]+)$')) stored;
+create index on torrent_files (extension);
+
+-- +goose StatementEnd