fix(search): lowercase pattern in Go, add buildSearchQuery unit tests

- Lowercase phrase/terms in Go (strings.ToLower) so SQL only needs LOWER() on the column side, avoiding redundant per-query LOWER() on the pattern - Add 5 unit tests for buildSearchQuery asserting SQL shape: no ILIKE, LOWER on columns only, lowercased args, multi-term AND, number match, include-closed flag, special char escaping Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-07-26 12:35:35 +02:00 · 2026-04-10 14:23:38 +08:00
parent 3464edacc4
commit a554a0c602
2 changed files with 126 additions and 25 deletions
--- a/server/internal/handler/issue.go
+++ b/server/internal/handler/issue.go
@@ -222,9 +222,15 @@ type searchResult struct {
 }

 // buildSearchQuery builds a dynamic SQL query for issue search.
-// It supports case-insensitive matching via LOWER/LIKE (pg_bigm compatible),
-// identifier search, multi-word search, and refined ranking.
+// It uses LOWER(column) LIKE for case-insensitive matching compatible with pg_bigm 1.2 GIN indexes.
+// Search patterns are lowercased in Go to avoid redundant LOWER() on the pattern side in SQL.
 func buildSearchQuery(phrase string, terms []string, queryNum int, hasNum bool, includeClosed bool) (string, []any) {
+	// Lowercase in Go so SQL only needs LOWER() on the column side.
+	phrase = strings.ToLower(phrase)
+	for i, t := range terms {
+		terms[i] = strings.ToLower(t)
+	}
+
 	// Parameter index tracker
 	argIdx := 1
 	args := []any{}
@@ -257,7 +263,7 @@ func buildSearchQuery(phrase string, terms []string, queryNum int, hasNum bool,

 	// Full phrase match: title, description, or comment
 	phraseMatch := fmt.Sprintf(
-		"(LOWER(i.title) LIKE LOWER(%s) OR LOWER(COALESCE(i.description, '')) LIKE LOWER(%s) OR EXISTS (SELECT 1 FROM comment c WHERE c.issue_id = i.id AND LOWER(c.content) LIKE LOWER(%s)))",
+		"(LOWER(i.title) LIKE %s OR LOWER(COALESCE(i.description, '')) LIKE %s OR EXISTS (SELECT 1 FROM comment c WHERE c.issue_id = i.id AND LOWER(c.content) LIKE %s))",
 		phraseContains, phraseContains, phraseContains,
 	)
 	whereParts = append(whereParts, phraseMatch)
@@ -268,7 +274,7 @@ func buildSearchQuery(phrase string, terms []string, queryNum int, hasNum bool,
 		for _, tp := range termParams {
 			tc := "'%' || " + tp + " || '%'"
 			termConditions = append(termConditions, fmt.Sprintf(
-				"(LOWER(i.title) LIKE LOWER(%s) OR LOWER(COALESCE(i.description, '')) LIKE LOWER(%s) OR EXISTS (SELECT 1 FROM comment c WHERE c.issue_id = i.id AND LOWER(c.content) LIKE LOWER(%s)))",
+				"(LOWER(i.title) LIKE %s OR LOWER(COALESCE(i.description, '')) LIKE %s OR EXISTS (SELECT 1 FROM comment c WHERE c.issue_id = i.id AND LOWER(c.content) LIKE %s))",
 				tc, tc, tc,
 			))
 		}
@@ -298,31 +304,31 @@ func buildSearchQuery(phrase string, terms []string, queryNum int, hasNum bool,
 	}

 	// Tier 1: Exact title match
-	rankCases = append(rankCases, fmt.Sprintf("WHEN LOWER(i.title) = LOWER(%s) THEN 1", phraseParam))
+	rankCases = append(rankCases, fmt.Sprintf("WHEN LOWER(i.title) = %s THEN 1", phraseParam))

 	// Tier 2: Title starts with phrase
-	rankCases = append(rankCases, fmt.Sprintf("WHEN LOWER(i.title) LIKE LOWER(%s) THEN 2", phraseStartsWith))
+	rankCases = append(rankCases, fmt.Sprintf("WHEN LOWER(i.title) LIKE %s THEN 2", phraseStartsWith))

 	// Tier 3: Title contains phrase
-	rankCases = append(rankCases, fmt.Sprintf("WHEN LOWER(i.title) LIKE LOWER(%s) THEN 3", phraseContains))
+	rankCases = append(rankCases, fmt.Sprintf("WHEN LOWER(i.title) LIKE %s THEN 3", phraseContains))

 	// Tier 4: Title matches all words (multi-word only)
 	if len(termParams) > 1 {
 		var titleTerms []string
 		for _, tp := range termParams {
-			titleTerms = append(titleTerms, fmt.Sprintf("LOWER(i.title) LIKE LOWER('%s' || %s || '%s')", "%", tp, "%"))
+			titleTerms = append(titleTerms, fmt.Sprintf("LOWER(i.title) LIKE '%s' || %s || '%s'", "%", tp, "%"))
 		}
 		rankCases = append(rankCases, fmt.Sprintf("WHEN (%s) THEN 4", strings.Join(titleTerms, " AND ")))
 	}

 	// Tier 5: Description contains phrase
-	rankCases = append(rankCases, fmt.Sprintf("WHEN LOWER(COALESCE(i.description, '')) LIKE LOWER(%s) THEN 5", phraseContains))
+	rankCases = append(rankCases, fmt.Sprintf("WHEN LOWER(COALESCE(i.description, '')) LIKE %s THEN 5", phraseContains))

 	// Tier 6: Description matches all words (multi-word only)
 	if len(termParams) > 1 {
 		var descTerms []string
 		for _, tp := range termParams {
-			descTerms = append(descTerms, fmt.Sprintf("LOWER(COALESCE(i.description, '')) LIKE LOWER('%s' || %s || '%s')", "%", tp, "%"))
+			descTerms = append(descTerms, fmt.Sprintf("LOWER(COALESCE(i.description, '')) LIKE '%s' || %s || '%s'", "%", tp, "%"))
 		}
 		rankCases = append(rankCases, fmt.Sprintf("WHEN (%s) THEN 6", strings.Join(descTerms, " AND ")))
 	}
@@ -343,8 +349,8 @@ func buildSearchQuery(phrase string, terms []string, queryNum int, hasNum bool,

 	// --- match_source expression ---
 	matchSourceExpr := fmt.Sprintf(`CASE
-		WHEN LOWER(i.title) LIKE LOWER(%s) THEN 'title'
-		WHEN LOWER(COALESCE(i.description, '')) LIKE LOWER(%s) THEN 'description'
+		WHEN LOWER(i.title) LIKE %s THEN 'title'
+		WHEN LOWER(COALESCE(i.description, '')) LIKE %s THEN 'description'
 		ELSE 'comment'
 	END`, phraseContains, phraseContains)

@@ -353,13 +359,13 @@ func buildSearchQuery(phrase string, terms []string, queryNum int, hasNum bool,
 		var titleTerms []string
 		var descTerms []string
 		for _, tp := range termParams {
-			titleTerms = append(titleTerms, fmt.Sprintf("LOWER(i.title) LIKE LOWER('%s' || %s || '%s')", "%", tp, "%"))
-			descTerms = append(descTerms, fmt.Sprintf("LOWER(COALESCE(i.description, '')) LIKE LOWER('%s' || %s || '%s')", "%", tp, "%"))
+			titleTerms = append(titleTerms, fmt.Sprintf("LOWER(i.title) LIKE '%s' || %s || '%s'", "%", tp, "%"))
+			descTerms = append(descTerms, fmt.Sprintf("LOWER(COALESCE(i.description, '')) LIKE '%s' || %s || '%s'", "%", tp, "%"))
 		}
 		matchSourceExpr = fmt.Sprintf(`CASE
-			WHEN LOWER(i.title) LIKE LOWER(%s) THEN 'title'
+			WHEN LOWER(i.title) LIKE %s THEN 'title'
 			WHEN (%s) THEN 'title'
-			WHEN LOWER(COALESCE(i.description, '')) LIKE LOWER(%s) THEN 'description'
+			WHEN LOWER(COALESCE(i.description, '')) LIKE %s THEN 'description'
 			WHEN (%s) THEN 'description'
 			ELSE 'comment'
 		END`,
@@ -371,11 +377,11 @@ func buildSearchQuery(phrase string, terms []string, queryNum int, hasNum bool,
 	// --- matched_comment_content subquery ---
 	// Find the most recent matching comment for comment-source matches.
 	commentSubquery := fmt.Sprintf(`CASE
-		WHEN LOWER(i.title) LIKE LOWER(%s) THEN ''
-		WHEN LOWER(COALESCE(i.description, '')) LIKE LOWER(%s) THEN ''
+		WHEN LOWER(i.title) LIKE %s THEN ''
+		WHEN LOWER(COALESCE(i.description, '')) LIKE %s THEN ''
 		ELSE COALESCE(
 			(SELECT c.content FROM comment c
-			 WHERE c.issue_id = i.id AND LOWER(c.content) LIKE LOWER(%s)
+			 WHERE c.issue_id = i.id AND LOWER(c.content) LIKE %s
 			 ORDER BY c.created_at DESC LIMIT 1),
 			''
 		)
@@ -387,18 +393,18 @@ func buildSearchQuery(phrase string, terms []string, queryNum int, hasNum bool,
 		var descTerms []string
 		var commentTerms []string
 		for _, tp := range termParams {
-			titleTerms = append(titleTerms, fmt.Sprintf("LOWER(i.title) LIKE LOWER('%s' || %s || '%s')", "%", tp, "%"))
-			descTerms = append(descTerms, fmt.Sprintf("LOWER(COALESCE(i.description, '')) LIKE LOWER('%s' || %s || '%s')", "%", tp, "%"))
-			commentTerms = append(commentTerms, fmt.Sprintf("LOWER(c.content) LIKE LOWER('%s' || %s || '%s')", "%", tp, "%"))
+			titleTerms = append(titleTerms, fmt.Sprintf("LOWER(i.title) LIKE '%s' || %s || '%s'", "%", tp, "%"))
+			descTerms = append(descTerms, fmt.Sprintf("LOWER(COALESCE(i.description, '')) LIKE '%s' || %s || '%s'", "%", tp, "%"))
+			commentTerms = append(commentTerms, fmt.Sprintf("LOWER(c.content) LIKE '%s' || %s || '%s'", "%", tp, "%"))
 		}
 		commentSubquery = fmt.Sprintf(`CASE
-			WHEN LOWER(i.title) LIKE LOWER(%s) THEN ''
+			WHEN LOWER(i.title) LIKE %s THEN ''
 			WHEN (%s) THEN ''
-			WHEN LOWER(COALESCE(i.description, '')) LIKE LOWER(%s) THEN ''
+			WHEN LOWER(COALESCE(i.description, '')) LIKE %s THEN ''
 			WHEN (%s) THEN ''
 			ELSE COALESCE(
 				(SELECT c.content FROM comment c
-				 WHERE c.issue_id = i.id AND (LOWER(c.content) LIKE LOWER(%s) OR (%s))
+				 WHERE c.issue_id = i.id AND (LOWER(c.content) LIKE %s OR (%s))
 				 ORDER BY c.created_at DESC LIMIT 1),
 				''
 			)
--- a/server/internal/handler/search_test.go
+++ b/server/internal/handler/search_test.go
@@ -0,0 +1,95 @@
+package handler
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestBuildSearchQuery_SingleTerm(t *testing.T) {
+	query, args := buildSearchQuery("Hello", []string{"Hello"}, 0, false, false)
+
+	// Pattern should be lowercased in Go.
+	if args[0] != "hello" {
+		t.Errorf("expected phrase arg to be lowercased, got %q", args[0])
+	}
+
+	// Must use LOWER(column) LIKE, not ILIKE.
+	if strings.Contains(query, "ILIKE") {
+		t.Error("query should not contain ILIKE")
+	}
+	if !strings.Contains(query, "LOWER(i.title) LIKE") {
+		t.Error("query should contain LOWER(i.title) LIKE")
+	}
+	if !strings.Contains(query, "LOWER(COALESCE(i.description, '')) LIKE") {
+		t.Error("query should contain LOWER(COALESCE(i.description, '')) LIKE")
+	}
+	if !strings.Contains(query, "LOWER(c.content) LIKE") {
+		t.Error("query should contain LOWER(c.content) LIKE")
+	}
+
+	// Exact title rank should not double-LOWER the pattern.
+	if strings.Contains(query, "LOWER(i.title) = LOWER(") {
+		t.Error("exact title rank should not wrap pattern in LOWER (already lowercased in Go)")
+	}
+	if !strings.Contains(query, "LOWER(i.title) = $1") {
+		t.Error("exact title rank should compare LOWER(i.title) = $1 directly")
+	}
+
+	// Should exclude closed issues by default.
+	if !strings.Contains(query, "NOT IN ('done', 'cancelled')") {
+		t.Error("query should exclude done/cancelled when includeClosed=false")
+	}
+}
+
+func TestBuildSearchQuery_MultiTerm(t *testing.T) {
+	query, args := buildSearchQuery("Foo Bar", []string{"Foo", "Bar"}, 0, false, false)
+
+	// Both phrase and terms should be lowercased.
+	if args[0] != "foo bar" {
+		t.Errorf("expected phrase arg lowercased, got %q", args[0])
+	}
+	// args[1] is workspace_id placeholder; term args start at args[2].
+	if args[2] != "foo" {
+		t.Errorf("expected first term arg lowercased, got %q", args[2])
+	}
+	if args[3] != "bar" {
+		t.Errorf("expected second term arg lowercased, got %q", args[3])
+	}
+
+	// Multi-word query should have AND conditions.
+	if !strings.Contains(query, " AND ") {
+		t.Error("multi-word query should contain AND conditions for per-term matching")
+	}
+}
+
+func TestBuildSearchQuery_WithNumber(t *testing.T) {
+	query, args := buildSearchQuery("MUL-42", []string{"MUL-42"}, 42, true, false)
+
+	_ = args
+	// Number match should be in WHERE.
+	if !strings.Contains(query, "i.number = ") {
+		t.Error("query should contain number match in WHERE clause")
+	}
+	// Tier 0 rank for identifier match.
+	if !strings.Contains(query, "THEN 0") {
+		t.Error("query should contain tier 0 rank for identifier match")
+	}
+}
+
+func TestBuildSearchQuery_IncludeClosed(t *testing.T) {
+	query, _ := buildSearchQuery("test", []string{"test"}, 0, false, true)
+
+	if strings.Contains(query, "NOT IN ('done', 'cancelled')") {
+		t.Error("query should not exclude done/cancelled when includeClosed=true")
+	}
+}
+
+func TestBuildSearchQuery_SpecialChars(t *testing.T) {
+	query, args := buildSearchQuery("100%", []string{"100%"}, 0, false, false)
+
+	_ = query
+	// % should be escaped in the phrase arg.
+	if escaped, ok := args[0].(string); !ok || !strings.Contains(escaped, `\%`) {
+		t.Errorf("expected %% to be escaped in phrase arg, got %q", args[0])
+	}
+}