Re-enable errcheck

.golangci.yml

@@ -3,15 +3,14 @@ linters:
   disable:
     - gochecknoglobals
     - gomnd
+    - nlreturn
     # TODO: re-enable these
-    - errcheck
     - funlen
     - testpackage
     # TODO: maybe re-enable these
     - godox
     - wsl
     - exhaustivestruct
-    - nlreturn
     - predeclared
     - ifshort
     # TODO: there seems to be a false positive here

client.go

@@ -195,7 +195,11 @@ func (c *Client) maybeStartPingLoop(wg *sync.WaitGroup, exiting chan struct{}) {
 func (c *Client) handlePing(timestamp int64, pongChan chan struct{}, wg *sync.WaitGroup, exiting chan struct{}) {
 	defer wg.Done()
 
-	c.Writef("PING :%d", timestamp)
+	err := c.Writef("PING :%d", timestamp)
+	if err != nil {
+		c.sendError(err)
+		return
+	}
 
 	timer := time.NewTimer(c.config.PingTimeout)
 	defer timer.Stop()
@@ -212,19 +216,28 @@ func (c *Client) handlePing(timestamp int64, pongChan chan struct{}, wg *sync.Wa
 
 // maybeStartCapHandshake will run a CAP LS and all the relevant CAP REQ
 // commands if there are any CAPs requested.
-func (c *Client) maybeStartCapHandshake() {
+func (c *Client) maybeStartCapHandshake() error {
 	if len(c.caps) == 0 {
-		return
+		return nil
+	}
+
+	err := c.Write("CAP LS")
+	if err != nil {
+		return err
 	}
 
-	c.Write("CAP LS")
 	c.remainingCapResponses = 1 // We count the CAP LS response as a normal response
 	for key, cap := range c.caps {
 		if cap.Requested {
-			c.Writef("CAP REQ :%s", key)
+			err = c.Writef("CAP REQ :%s", key)
+			if err != nil {
+				return err
+			}
 			c.remainingCapResponses++
 		}
 	}
+
+	return nil
 }
 
 // CapRequest allows you to request IRCv3 capabilities from the server during
@@ -282,11 +295,11 @@ func (c *Client) startReadLoop(wg *sync.WaitGroup, exiting chan struct{}) {
 				}
 
 				if c.ISupport != nil {
-					c.ISupport.Handle(m)
+					_ = c.ISupport.Handle(m)
 				}
 
 				if c.Tracker != nil {
-					c.Tracker.Handle(m)
+					_ = c.Tracker.Handle(m)
 				}
 
 				if c.config.Handler != nil {
@@ -316,23 +329,34 @@ func (c *Client) RunContext(ctx context.Context) error {
 	c.maybeStartPingLoop(&wg, exiting)
 
 	if c.config.Pass != "" {
-		c.Writef("PASS :%s", c.config.Pass)
+		err := c.Writef("PASS :%s", c.config.Pass)
+		if err != nil {
+			return err
+		}
 	}
 
-	c.maybeStartCapHandshake()
+	err := c.maybeStartCapHandshake()
+	if err != nil {
+		return err
+	}
 
 	// This feels wrong because it results in CAP LS, CAP REQ, NICK, USER, CAP
 	// END, but it works and lets us keep the code a bit simpler.
-	c.Writef("NICK :%s", c.config.Nick)
-	c.Writef("USER %s 0 * :%s", c.config.User, c.config.Name)
+	err = c.Writef("NICK :%s", c.config.Nick)
+	if err != nil {
+		return err
+	}
+	err = c.Writef("USER %s 0 * :%s", c.config.User, c.config.Name)
+	if err != nil {
+		return err
+	}
 
 	// Now that the handshake is pretty much done, we can start listening for
 	// messages.
 	c.startReadLoop(&wg, exiting)
 
 	// Wait for an error from any goroutine or for the context to time out, then
 	// signal we're exiting and wait for the goroutines to exit.
-	var err error
 	select {
 	case err = <-c.errChan:
 	case <-ctx.Done():

client_handlers.go

@@ -45,7 +45,7 @@ func handle433(c *Client, m *Message) {
 		return
 	}
 	c.currentNick += "_"
-	c.Writef("NICK :%s", c.currentNick)
+	_ = c.Writef("NICK :%s", c.currentNick)
 }
 
 // From rfc2812 section 5.2 (Error Replies)
@@ -66,13 +66,13 @@ func handle437(c *Client, m *Message) {
 		return
 	}
 	c.currentNick += "_"
-	c.Writef("NICK :%s", c.currentNick)
+	_ = c.Writef("NICK :%s", c.currentNick)
 }
 
 func handlePing(c *Client, m *Message) {
 	reply := m.Copy()
 	reply.Command = "PONG"
-	c.WriteMessage(reply)
+	_ = c.WriteMessage(reply)
 }
 
 func handlePong(c *Client, m *Message) {
@@ -116,7 +116,7 @@ func handleCap(c *Client, m *Message) {
 			}
 		}
 
-		c.Write("CAP END")
+		_ = c.Write("CAP END")
 	}
 }
 

conn_test.go

@@ -100,13 +100,15 @@ func TestConn(t *testing.T) {
 
 	// Test writing a message
 	m := &Message{Prefix: &Prefix{}, Command: "PING", Params: []string{"Hello World"}}
-	c.WriteMessage(m)
+	err := c.WriteMessage(m)
+	assert.NoError(t, err)
 	testLines(t, rwc, []string{
 		"PING :Hello World",
 	})
 
 	// Test with Writef
-	c.Writef("PING :%s", "Hello World")
+	err = c.Writef("PING :%s", "Hello World")
+	assert.NoError(t, err)
 	testLines(t, rwc, []string{
 		"PING :Hello World",
 	})
@@ -124,7 +126,7 @@ func TestConn(t *testing.T) {
 	assert.EqualValues(t, m, m2, "Message returned by client did not match input")
 
 	rwc.server.WriteString(":invalid_message\r\n")
-	_, err := c.ReadMessage()
+	_, err = c.ReadMessage()
 	assert.Equal(t, ErrMissingDataAfterPrefix, err)
 
 	// Ensure empty messages are ignored
@@ -154,7 +156,8 @@ func TestDebugCallback(t *testing.T) {
 	}
 
 	m := &Message{Prefix: &Prefix{}, Command: "PING", Params: []string{"Hello World"}}
-	c.WriteMessage(m)
+	err := c.WriteMessage(m)
+	assert.NoError(t, err)
 	testLines(t, rwc, []string{
 		"PING :Hello World",
 	})

parser.go

@@ -140,7 +140,7 @@ func (t Tags) String() string {
 
 	// We don't need the first byte because that's an extra ';'
 	// character.
-	buf.ReadByte()
+	_, _ = buf.ReadByte()
 
 	return buf.String()
 }