Require access to ConnString via Config

A Config object may be created via ParseConfig and then further
modified. Requiring access to the original ConnString via the Config
helps indicate that the Config is the source of truth as to how the
connection was actually established.

conn.go

@@ -424,9 +424,6 @@ func (c *Conn) StatementCache() stmtcache.Cache { return c.stmtcache }
 // ConnInfo returns the connection info used for this connection.
 func (c *Conn) ConnInfo() *pgtype.ConnInfo { return c.connInfo }
 
-// ConnString returns the connection string that was used to establish this connection.
-func (c *Conn) ConnString() string { return c.config.ConnString() }
-
 // Config returns config that was used to establish this connection.
 func (c *Conn) Config() *ConnConfig { return c.config }
 

conn_test.go

@@ -29,7 +29,6 @@ func TestCrateDBConnect(t *testing.T) {
 	defer closeConn(t, conn)
 
 	assert.Equal(t, connString, conn.Config().ConnString())
-	assert.Equal(t, connString, conn.ConnString())
 
 	var result int
 	err = conn.QueryRow(context.Background(), "select 1 +1").Scan(&result)
@@ -53,7 +52,6 @@ func TestConnect(t *testing.T) {
 	}
 
 	assert.Equal(t, connString, conn.Config().ConnString())
-	assert.Equal(t, connString, conn.ConnString())
 
 	var currentDB string
 	err = conn.QueryRow(context.Background(), "select current_database()").Scan(&currentDB)

pgxpool/pool.go

@@ -121,6 +121,8 @@ type Config struct {
 	createdByParseConfig bool // Used to enforce created by ParseConfig rule.
 }
 
+func (c *Config) ConnString() string { return c.ConnConfig.ConnString() }
+
 // Connect creates a new Pool and immediately establishes one connection. ctx can be used to cancel this initial
 // connection. See ParseConfig for information on connString format.
 func Connect(ctx context.Context, connString string) (*Pool, error) {
@@ -371,9 +373,6 @@ func (p *Pool) AcquireAllIdle(ctx context.Context) []*Conn {
 	return conns
 }
 
-// ConnString returns the connection string that was used to initialize this pool.
-func (p *Pool) ConnString() string { return p.config.ConnConfig.ConnString() }
-
 // Config returns config that was used to initialize this pool.
 func (p *Pool) Config() *Config { return p.config }
 

pgxpool/pool_test.go

@@ -17,7 +17,7 @@ func TestConnect(t *testing.T) {
 	connString := os.Getenv("PGX_TEST_DATABASE")
 	pool, err := pgxpool.Connect(context.Background(), connString)
 	require.NoError(t, err)
-	assert.Equal(t, connString, pool.ConnString())
+	assert.Equal(t, connString, pool.Config().ConnString())
 	pool.Close()
 }