test(pgsql, reflectutil): ✨ add comprehensive test coverage

* Introduce tests for PostgreSQL data types and keywords.
* Implement tests for reflect utility functions.
* Ensure consistency and correctness of type conversions and keyword mappings.
* Validate behavior for various edge cases and input types.

pkg/pgsql/keywords_test.go

@@ -0,0 +1,136 @@
+package pgsql
+
+import (
+	"testing"
+)
+
+func TestGetPostgresKeywords(t *testing.T) {
+	keywords := GetPostgresKeywords()
+
+	// Test that keywords are returned
+	if len(keywords) == 0 {
+		t.Fatal("Expected non-empty list of keywords")
+	}
+
+	// Test that we get all keywords from the map
+	expectedCount := len(postgresKeywords)
+	if len(keywords) != expectedCount {
+		t.Errorf("Expected %d keywords, got %d", expectedCount, len(keywords))
+	}
+
+	// Test that all returned keywords exist in the map
+	for _, keyword := range keywords {
+		if !postgresKeywords[keyword] {
+			t.Errorf("Keyword %q not found in postgresKeywords map", keyword)
+		}
+	}
+
+	// Test that no duplicate keywords are returned
+	seen := make(map[string]bool)
+	for _, keyword := range keywords {
+		if seen[keyword] {
+			t.Errorf("Duplicate keyword found: %q", keyword)
+		}
+		seen[keyword] = true
+	}
+}
+
+func TestPostgresKeywordsMap(t *testing.T) {
+	tests := []struct {
+		name    string
+		keyword string
+		want    bool
+	}{
+		{"SELECT keyword", "select", true},
+		{"FROM keyword", "from", true},
+		{"WHERE keyword", "where", true},
+		{"TABLE keyword", "table", true},
+		{"PRIMARY keyword", "primary", true},
+		{"FOREIGN keyword", "foreign", true},
+		{"CREATE keyword", "create", true},
+		{"DROP keyword", "drop", true},
+		{"ALTER keyword", "alter", true},
+		{"INDEX keyword", "index", true},
+		{"NOT keyword", "not", true},
+		{"NULL keyword", "null", true},
+		{"TRUE keyword", "true", true},
+		{"FALSE keyword", "false", true},
+		{"Non-keyword lowercase", "notakeyword", false},
+		{"Non-keyword uppercase", "NOTAKEYWORD", false},
+		{"Empty string", "", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := postgresKeywords[tt.keyword]
+			if got != tt.want {
+				t.Errorf("postgresKeywords[%q] = %v, want %v", tt.keyword, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestPostgresKeywordsMapContent(t *testing.T) {
+	// Test that the map contains expected common keywords
+	commonKeywords := []string{
+		"select", "insert", "update", "delete", "create", "drop", "alter",
+		"table", "index", "view", "schema", "function", "procedure",
+		"primary", "foreign", "key", "constraint", "unique", "check",
+		"null", "not", "and", "or", "like", "in", "between",
+		"join", "inner", "left", "right", "cross", "full", "outer",
+		"where", "having", "group", "order", "limit", "offset",
+		"union", "intersect", "except",
+		"begin", "commit", "rollback", "transaction",
+	}
+
+	for _, keyword := range commonKeywords {
+		if !postgresKeywords[keyword] {
+			t.Errorf("Expected common keyword %q to be in postgresKeywords map", keyword)
+		}
+	}
+}
+
+func TestPostgresKeywordsMapSize(t *testing.T) {
+	// PostgreSQL has a substantial list of reserved keywords
+	// This test ensures the map has a reasonable number of entries
+	minExpectedKeywords := 200 // PostgreSQL 13+ has 400+ reserved words
+
+	if len(postgresKeywords) < minExpectedKeywords {
+		t.Errorf("Expected at least %d keywords, got %d. The map may be incomplete.",
+			minExpectedKeywords, len(postgresKeywords))
+	}
+}
+
+func TestGetPostgresKeywordsConsistency(t *testing.T) {
+	// Test that calling GetPostgresKeywords multiple times returns consistent results
+	keywords1 := GetPostgresKeywords()
+	keywords2 := GetPostgresKeywords()
+
+	if len(keywords1) != len(keywords2) {
+		t.Errorf("Inconsistent results: first call returned %d keywords, second call returned %d",
+			len(keywords1), len(keywords2))
+	}
+
+	// Create a map from both results to compare
+	map1 := make(map[string]bool)
+	map2 := make(map[string]bool)
+
+	for _, k := range keywords1 {
+		map1[k] = true
+	}
+	for _, k := range keywords2 {
+		map2[k] = true
+	}
+
+	// Check that both contain the same keywords
+	for k := range map1 {
+		if !map2[k] {
+			t.Errorf("Keyword %q present in first call but not in second", k)
+		}
+	}
+	for k := range map2 {
+		if !map1[k] {
+			t.Errorf("Keyword %q present in second call but not in first", k)
+		}
+	}
+}