feat(memory/vector): 向量检索引擎（SQLite BLOB 内积默认 + PG pgvector 真语义增强，配置后真生效）

internal/runtime/memory/vector/pg_test.go

@@ -0,0 +1,92 @@
+package vector
+
+import (
+	"context"
+	"errors"
+	"os"
+	"testing"
+)
+
+func TestNewPG_InvalidURL_异常(t *testing.T) {
+	t.Parallel()
+	if _, err := NewPG(context.Background(), "   ", 4, testLogger()); !errors.Is(err, ErrInvalidPGURL) {
+		t.Fatalf("NewPG(blank url) err = %v, want ErrInvalidPGURL", err)
+	}
+}
+
+func TestNewPG_InvalidDim_异常(t *testing.T) {
+	t.Parallel()
+	// dim is validated before any connection is opened, so no network I/O here.
+	if _, err := NewPG(context.Background(), "postgres://host/db", 0, testLogger()); !errors.Is(err, ErrInvalidDim) {
+		t.Fatalf("NewPG(dim 0) err = %v, want ErrInvalidDim", err)
+	}
+}
+
+func TestPGVectorLiteral(t *testing.T) {
+	t.Parallel()
+	tests := []struct {
+		name string
+		v    Vector
+		want string
+	}{
+		{name: "single", v: Vector{1}, want: "[1]"},
+		{name: "three", v: Vector{1.5, 2, -0.25}, want: "[1.5,2,-0.25]"},
+		{name: "empty", v: Vector{}, want: "[]"},
+	}
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			if got := pgVectorLiteral(tt.v); got != tt.want {
+				t.Fatalf("pgVectorLiteral(%v) = %q, want %q", tt.v, got, tt.want)
+			}
+		})
+	}
+}
+
+// TestPG_RequiresEnv runs a real PostgreSQL+pgvector round trip when DB_PG_URL
+// is set, and skips otherwise. There is no PG server in this environment by
+// default, so the pgvector-backed Add/Search path is validated end-to-end only
+// when the operator supplies a live database with the pgvector extension. The
+// SQLite path (the default) is fully covered by the sqlite_test.go suite.
+func TestPG_RequiresEnv(t *testing.T) {
+	url := os.Getenv("DB_PG_URL")
+	if url == "" {
+		t.Skip("DB_PG_URL not set; skipping real PostgreSQL+pgvector integration test")
+	}
+
+	ctx := context.Background()
+	idx, err := NewPG(ctx, url, 4, testLogger())
+	if err != nil {
+		t.Fatalf("NewPG: %v", err)
+	}
+	idx.withEmbedder(&mockEmbedder{dim: 4})
+	defer func() { _ = idx.Close() }()
+
+	if err := idx.Add(ctx, "a", Vector{1, 0, 0, 0}); err != nil {
+		t.Fatalf("Add a: %v", err)
+	}
+	if err := idx.Add(ctx, "b", Vector{0, 1, 0, 0}); err != nil {
+		t.Fatalf("Add b: %v", err)
+	}
+
+	hits, err := idx.Search(ctx, Vector{1, 0, 0, 0}, 1)
+	if err != nil {
+		t.Fatalf("Search: %v", err)
+	}
+	if len(hits) != 1 || hits[0].ID != "a" {
+		t.Fatalf("pg top hit = %+v, want single a", hits)
+	}
+	if hits[0].Score < 0.99 {
+		t.Fatalf("pg a score = %v, want ~1.0", hits[0].Score)
+	}
+
+	// The embedder is wired, so Index.Embed is usable.
+	vs, err := idx.Embed(ctx, []string{"hello"})
+	if err != nil {
+		t.Fatalf("Embed: %v", err)
+	}
+	if len(vs) != 1 || len(vs[0]) != 4 {
+		t.Fatalf("Embed => %d vectors, want one 4-dim", len(vs))
+	}
+}