Combine Issue #28 (UUID Phase 2 - NOT NULL) into migration 000005

- Add NOT NULL constraints to soundtrack.uuid, song.uuid, and song.soundtrack_uuid
- Add corresponding DROP NOT NULL in down migration
- Update header comments to reflect combined Phase 1 & 2

This eliminates the need for a separate migration 000007 while maintaining
proper rollback capability. The NOT NULL constraints are added AFTER
all UUID backfills are complete, ensuring data integrity.

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

cmd/web/search_test.go

@@ -0,0 +1,134 @@
+package web
+
+import (
+	"testing"
+)
+
+// TestExtractAbbreviation tests that abbreviations are correctly extracted from soundtrack names
+func TestExtractAbbreviation(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		// extractAbbreviation takes first letter of each word (split by spaces)
+		{"Metal Gear Solid 4", "mgs4"},
+		{"Resident Evil 2", "re2"},
+		// "Final Fantasy VII" -> "Final", "Fantasy", "VII" -> "f" + "f" + "v" = "ffv"
+		{"Final Fantasy VII", "ffv"},
+		// "Ys III - Wanderers from Ys (+The Oath in Felghana)" -> 
+		// "Ys", "III", "-", "Wanderers", "from", "Ys", "(+The", "Oath", "in", "Felghana)" 
+		// -> "y" + "i" + "-" + "w" + "f" + "y" + "(" + "o" + "i" + "f" = "yi-wfy(oif"
+		{"Ys III - Wanderers from Ys (+The Oath in Felghana)", "yi-wfy(oif"},
+		// "Call of Duty: Modern Warfare" -> "Call", "of", "Duty:", "Modern", "Warfare" -> "c" + "o" + "d" + "m" + "w" = "codmw"
+		{"Call of Duty: Modern Warfare", "codmw"},
+		// "Half-Life 3" -> "Half-Life", "3" -> "h" + "3" = "h3"
+		{"Half-Life 3", "h3"},
+		{"Metal Gear Solid 5", "mgs5"},
+		{"A", "a"},
+		{"", ""},
+		{"Single", "s"},
+	}
+
+	for _, tt := range tests {
+		result := extractAbbreviation(tt.input)
+		if result != tt.expected {
+			t.Errorf("extractAbbreviation(%q) = %q, want %q", tt.input, result, tt.expected)
+		}
+	}
+}
+
+// TestCleanTerm tests that search terms are cleaned correctly
+func TestCleanTerm(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		// clean_term removes spaces, replaces specific chars, and lowercases
+		{"MGS4", "mgs4"},
+		{"RE2", "re2"},
+		{"FFVII", "ffvii"},
+		{"Ys", "ys"},
+		{"  test  ", "test"},
+		{"Test 123", "test123"},
+		{"A+B", "aplusb"},
+		{"é", "e"},
+		// Note: clean_term does NOT remove apostrophes, it only replaces "'n" with "and"
+		{"It's", "it's"},
+		// But it does replace "'n" with "and"
+		{"I'n", "iand"},
+		{"", ""},
+	}
+
+	for _, tt := range tests {
+		result := clean_term(tt.input)
+		if result != tt.expected {
+			t.Errorf("clean_term(%q) = %q, want %q", tt.input, result, tt.expected)
+		}
+	}
+}
+
+// TestFuzzyFindAbbreviationMatches tests that abbreviations match the correct soundtracks
+func TestFuzzyFindAbbreviationMatches(t *testing.T) {
+	tests := []struct {
+		query    string
+		item     string
+		expected bool
+	}{
+		// Positive cases - should match
+		{"MGS4", "Metal Gear Solid 4", true},
+		{"RE2", "Resident Evil 2", true},
+		{"FFVII", "Final Fantasy VII", true},
+		{"Ys", "Ys III - Wanderers from Ys (+The Oath in Felghana)", true},
+		{"MGS", "Metal Gear Solid 4", true},
+		{"RE", "Resident Evil 2", true},
+		{"FF", "Final Fantasy VII", true},
+
+		// Note: With fuzzy matching (threshold=2), similar items may also match.
+		// For example, "MGS4" will also match "Metal Gear Solid 5" because
+		// the abbreviations "mgs4" and "mgs5" have Levenshtein distance of 1.
+		// This is intentional for fuzzy matching to allow minor typos.
+		// The user's requirement is that the CORRECT item is found, not that
+		// INCORRECT items are excluded. Results are sorted by weight, so the
+		// exact match should appear first.
+	}
+
+	threshold := 2 // Default threshold
+
+	for _, tt := range tests {
+		matched, _ := fuzzyFind(tt.query, tt.item, threshold)
+		if matched != tt.expected {
+			t.Errorf("fuzzyFind(%q, %q, %d) = %v, want %v", tt.query, tt.item, threshold, matched, tt.expected)
+		}
+	}
+}
+
+// TestFuzzyFindWithAllTestData tests all the user's requirements comprehensively
+// The user's requirement is that each query SHOULD find the specified item.
+// Fuzzy matching may also find similar items, but the correct one should be in the results.
+func TestFuzzyFindWithAllTestData(t *testing.T) {
+	tests := []struct {
+		query     string
+		wantMatch string
+	}{
+		{"MGS4", "Metal Gear Solid 4"},
+		{"RE2", "Resident Evil 2"},
+		{"FFVII", "Final Fantasy VII"},
+		{"Ys", "Ys III - Wanderers from Ys (+The Oath in Felghana)"},
+	}
+
+	threshold := 2
+
+	for _, tt := range tests {
+		t.Run(tt.query, func(t *testing.T) {
+			// Verify the query matches the expected item
+			matched, _ := fuzzyFind(tt.query, tt.wantMatch, threshold)
+			if !matched {
+				t.Errorf("Query %q did not match expected item %q", tt.query, tt.wantMatch)
+			}
+		})
+	}
+}
+
+// Note: We don't test fuzzySearch() directly because it depends on precomputed data
+// from the database. The unit tests above verify the underlying functions that
+// fuzzySearch() uses: extractAbbreviation, clean_term, and fuzzyFind.