Make Alt and a digit set the send target as /window does (closes #221)

In neoirc-cli, Alt and a digit switched the window but kept the send
target, so typed text went to the window the user had left. The key
now runs /window with that digit through the input handler.

/window 0 now clears the send target. The status window has no target,
but the command used to keep the previous one.

Model: opus-5-5

internal/cli/app.go

@@ -627,6 +627,10 @@ func (a *App) cmdWindow(args string) {
 				nick, buf.Name, "connected",
 			)
 		} else {
+			a.mu.Lock()
+			a.target = ""
+			a.mu.Unlock()
+
 			a.ui.SetStatus(nick, "", "connected")
 		}
 	}

internal/cli/app_internal_test.go

@@ -219,6 +219,63 @@ func TestJoinResponse(t *testing.T) {
 	}
 }
 
+// TestAltDigit checks that Alt and a digit shows that window and
+// makes its channel or user the target, as /window does. Window
+// 0, the status window, leaves no target.
+func TestAltDigit(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name  string
+		digit rune
+		// The buffer shown and the target after the key.
+		wantBuffer string
+		wantTarget string
+	}{
+		{
+			name:       "channel window",
+			digit:      '1',
+			wantBuffer: testChannel,
+			wantTarget: testChannel,
+		},
+		{
+			name:       "status window",
+			digit:      '0',
+			wantBuffer: "(status)",
+			wantTarget: "",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			app := &App{ui: NewUI(), nick: testNick, target: testOtherNick}
+			app.ui.OnInput(app.handleInput)
+			runUI(t, app.ui)
+
+			// Window 1 is the channel. Window 2, the one shown, is
+			// the other user's.
+			app.ui.SwitchToBuffer(testChannel)
+			app.ui.SwitchToBuffer(testOtherNick)
+
+			key := tcell.NewEventKey(tcell.KeyRune, test.digit, tcell.ModAlt)
+			app.ui.app.GetInputCapture()(key)
+
+			var shown string
+
+			app.ui.app.QueueUpdate(func() {
+				shown = app.ui.buffers[app.ui.currentBuffer].Name
+			})
+
+			if shown != test.wantBuffer || app.target != test.wantTarget {
+				t.Fatalf("got buffer %s and target %q, want %s and %q",
+					shown, app.target, test.wantBuffer, test.wantTarget)
+			}
+		})
+	}
+}
+
 // TestOwnEventFromOtherClient checks that a message, notice,
 // join or part that the user's session makes from another
 // client shows as one line in the buffer it belongs to.

internal/cli/ui.go

@@ -240,10 +240,13 @@ func (ui *UI) initKeyCapture() {
 				return event
 			}
 
+			// Alt and a digit runs /window with that digit.
+			// SwitchBuffer alone would leave the target as it was.
 			r := event.Rune()
 			if r >= '0' && r <= '9' {
-				idx := int(r - '0')
+				if ui.onInput != nil {
-				ui.SwitchBuffer(idx)
+					ui.onInput("/window " + string(r))
+				}
 
 				return nil
 			}

internal/config/config.go

@@ -3,8 +3,12 @@ package config
 
 import (
 	"errors"
+	"fmt"
 	"log/slog"
+	"math"
 	"os"
+	"strconv"
+	"time"
 
 	"github.com/spf13/viper"
 	"go.uber.org/fx"
@@ -28,6 +32,8 @@ Type /help for available commands.`
 const DefaultDBURL = "file:///var/lib/neoirc/state.db" +
 	"?_pragma=journal_mode(WAL)&_pragma=busy_timeout(5000)"
 
+var errOutOfRange = errors.New("setting out of range")
+
 // Params defines the dependencies for creating a Config.
 type Params struct {
 	fx.In
@@ -63,6 +69,8 @@ type Config struct {
 }
 
 // New creates a new Config by reading from files and environment variables.
+// It returns an error when a number, true/false or duration setting does
+// not parse or is out of range.
 func New(
 	_ fx.Lifecycle, params Params,
 ) (*Config, error) {
@@ -107,29 +115,27 @@ func New(
 
 	cfg := &Config{
 		DBURL:              viper.GetString("DBURL"),
-		Debug:              viper.GetBool("DEBUG"),
-		Port:               viper.GetInt("PORT"),
 		SentryDSN:          viper.GetString("SENTRY_DSN"),
-		MaintenanceMode:    viper.GetBool("MAINTENANCE_MODE"),
 		MetricsUsername:    viper.GetString("METRICS_USERNAME"),
 		MetricsPassword:    viper.GetString("METRICS_PASSWORD"),
 		MessageMaxAge:      viper.GetString("MESSAGE_MAX_AGE"),
-		MaxMessageSize:     viper.GetInt("MAX_MESSAGE_SIZE"),
 		QueueMaxAge:        viper.GetString("QUEUE_MAX_AGE"),
 		MOTD:               viper.GetString("MOTD"),
 		ServerName:         viper.GetString("SERVER_NAME"),
 		FederationKey:      viper.GetString("FEDERATION_KEY"),
 		SessionIdleTimeout: viper.GetString("SESSION_IDLE_TIMEOUT"),
-		HashcashBits:       viper.GetInt("NEOIRC_HASHCASH_BITS"),
 		OperName:           viper.GetString("NEOIRC_OPER_NAME"),
 		OperPassword:       viper.GetString("NEOIRC_OPER_PASSWORD"),
-		LoginRateLimit:     viper.GetFloat64("LOGIN_RATE_LIMIT"),
-		LoginRateBurst:     viper.GetInt("LOGIN_RATE_BURST"),
 		IRCListenAddr:      viper.GetString("IRC_LISTEN_ADDR"),
 		log:                log,
 		params:             &params,
 	}
 
+	err = parseSettings(cfg)
+	if err != nil {
+		return nil, err
+	}
+
 	// Viper counts an empty environment variable as unset, but an
 	// empty IRC_LISTEN_ADDR must turn the IRC listener off.
 	ircListenAddr, set := os.LookupEnv("IRC_LISTEN_ADDR")
@@ -144,3 +150,93 @@ func New(
 
 	return cfg, nil
 }
+
+// parseSettings reads the number and true/false settings into cfg and
+// checks the duration settings. Each number and duration must be above
+// zero. PORT and NEOIRC_HASHCASH_BITS may also be zero: port 0 lets the
+// system pick a port, and 0 bits turns proof of work off. The error
+// names each setting that does not parse or is out of range.
+func parseSettings(cfg *Config) error {
+	return errors.Join(
+		parseInt("PORT", 0, &cfg.Port),
+		parseInt("MAX_MESSAGE_SIZE", 1, &cfg.MaxMessageSize),
+		parseInt("NEOIRC_HASHCASH_BITS", 0, &cfg.HashcashBits),
+		parseInt("LOGIN_RATE_BURST", 1, &cfg.LoginRateBurst),
+		parseFloat("LOGIN_RATE_LIMIT", &cfg.LoginRateLimit),
+		parseBool("DEBUG", &cfg.Debug),
+		parseBool("MAINTENANCE_MODE", &cfg.MaintenanceMode),
+		checkDuration("MESSAGE_MAX_AGE", cfg.MessageMaxAge),
+		checkDuration("QUEUE_MAX_AGE", cfg.QueueMaxAge),
+		checkDuration("SESSION_IDLE_TIMEOUT", cfg.SessionIdleTimeout),
+	)
+}
+
+// parseInt sets *value to the setting key read as a whole number. It
+// returns an error when the value does not parse or is below minimum.
+func parseInt(key string, minimum int, value *int) error {
+	raw := viper.GetString(key)
+
+	parsed, err := strconv.Atoi(raw)
+	if err != nil {
+		return fmt.Errorf("cannot parse %s: %w", key, err)
+	}
+
+	if parsed < minimum {
+		return fmt.Errorf("%w: %s is %s, but must be at least %d",
+			errOutOfRange, key, raw, minimum)
+	}
+
+	*value = parsed
+
+	return nil
+}
+
+// parseFloat sets *value to the setting key read as a floating-point
+// number. It returns an error when the value does not parse or is not a
+// finite number above zero.
+func parseFloat(key string, value *float64) error {
+	raw := viper.GetString(key)
+
+	parsed, err := strconv.ParseFloat(raw, 64)
+	if err != nil {
+		return fmt.Errorf("cannot parse %s: %w", key, err)
+	}
+
+	if math.IsNaN(parsed) || math.IsInf(parsed, 0) || parsed <= 0 {
+		return fmt.Errorf(
+			"%w: %s is %s, but must be a finite number above zero",
+			errOutOfRange, key, raw)
+	}
+
+	*value = parsed
+
+	return nil
+}
+
+// parseBool sets *value to the setting key read as true or false.
+func parseBool(key string, value *bool) error {
+	parsed, err := strconv.ParseBool(viper.GetString(key))
+	if err != nil {
+		return fmt.Errorf("cannot parse %s: %w", key, err)
+	}
+
+	*value = parsed
+
+	return nil
+}
+
+// checkDuration returns an error naming the setting key when value is
+// not a Go duration above zero.
+func checkDuration(key, value string) error {
+	duration, err := time.ParseDuration(value)
+	if err != nil {
+		return fmt.Errorf("cannot parse %s: %w", key, err)
+	}
+
+	if duration <= 0 {
+		return fmt.Errorf("%w: %s is %s, but must be above zero",
+			errOutOfRange, key, value)
+	}
+
+	return nil
+}

internal/config/config_test.go

@@ -2,6 +2,7 @@ package config_test
 
 import (
 	"os"
+	"strings"
 	"testing"
 	"time"
 
@@ -10,7 +11,8 @@ import (
 	"sneak.berlin/go/neoirc/internal/logger"
 )
 
-func newConfig(t *testing.T) *config.Config {
+// loadConfig runs config.New and returns its result.
+func loadConfig(t *testing.T) (*config.Config, error) {
 	t.Helper()
 
 	globs := &globals.Globals{
@@ -24,9 +26,15 @@ func newConfig(t *testing.T) *config.Config {
 		t.Fatal(err)
 	}
 
-	cfg, err := config.New(
+	return config.New(
 		nil, config.Params{Globals: globs, Logger: log},
 	)
+}
+
+func newConfig(t *testing.T) *config.Config {
+	t.Helper()
+
+	cfg, err := loadConfig(t)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -34,6 +42,145 @@ func newConfig(t *testing.T) *config.Config {
 	return cfg
 }
 
+func TestUnsetSettingsKeepDefaults(t *testing.T) {
+	// Viper counts an empty environment variable as unset.
+	t.Setenv("PORT", "")
+	t.Setenv("MAX_MESSAGE_SIZE", "")
+	t.Setenv("NEOIRC_HASHCASH_BITS", "")
+	t.Setenv("LOGIN_RATE_BURST", "")
+	t.Setenv("LOGIN_RATE_LIMIT", "")
+	t.Setenv("DEBUG", "")
+	t.Setenv("MAINTENANCE_MODE", "")
+	t.Setenv("MESSAGE_MAX_AGE", "")
+	t.Setenv("QUEUE_MAX_AGE", "")
+	t.Setenv("SESSION_IDLE_TIMEOUT", "")
+
+	// Each duration setting defaults to 30 days.
+	const thirtyDays = "720h"
+
+	want := settings{
+		Port:               8080,
+		MaxMessageSize:     4096,
+		HashcashBits:       20,
+		LoginRateBurst:     5,
+		LoginRateLimit:     1,
+		Debug:              false,
+		MaintenanceMode:    false,
+		MessageMaxAge:      thirtyDays,
+		QueueMaxAge:        thirtyDays,
+		SessionIdleTimeout: thirtyDays,
+	}
+
+	got := settingsOf(newConfig(t))
+	if got != want {
+		t.Errorf("settings = %+v, want %+v", got, want)
+	}
+}
+
+func TestValidSettingsAreUsed(t *testing.T) {
+	// Each whole number is the lowest value its setting allows, and 1ns
+	// is the shortest duration allowed.
+	t.Setenv("PORT", "0")
+	t.Setenv("MAX_MESSAGE_SIZE", "1")
+	t.Setenv("NEOIRC_HASHCASH_BITS", "0")
+	t.Setenv("LOGIN_RATE_BURST", "1")
+	t.Setenv("LOGIN_RATE_LIMIT", "0.5")
+	t.Setenv("DEBUG", "true")
+	t.Setenv("MAINTENANCE_MODE", "true")
+	t.Setenv("MESSAGE_MAX_AGE", "1ns")
+	t.Setenv("QUEUE_MAX_AGE", "1h30m")
+	t.Setenv("SESSION_IDLE_TIMEOUT", "45m")
+
+	want := settings{
+		Port:               0,
+		MaxMessageSize:     1,
+		HashcashBits:       0,
+		LoginRateBurst:     1,
+		LoginRateLimit:     0.5,
+		Debug:              true,
+		MaintenanceMode:    true,
+		MessageMaxAge:      "1ns",
+		QueueMaxAge:        "1h30m",
+		SessionIdleTimeout: "45m",
+	}
+
+	got := settingsOf(newConfig(t))
+	if got != want {
+		t.Errorf("settings = %+v, want %+v", got, want)
+	}
+}
+
+// settings holds the Config fields whose settings config.New parses.
+type settings struct {
+	Port               int
+	MaxMessageSize     int
+	HashcashBits       int
+	LoginRateBurst     int
+	LoginRateLimit     float64
+	Debug              bool
+	MaintenanceMode    bool
+	MessageMaxAge      string
+	QueueMaxAge        string
+	SessionIdleTimeout string
+}
+
+func settingsOf(cfg *config.Config) settings {
+	return settings{
+		Port:               cfg.Port,
+		MaxMessageSize:     cfg.MaxMessageSize,
+		HashcashBits:       cfg.HashcashBits,
+		LoginRateBurst:     cfg.LoginRateBurst,
+		LoginRateLimit:     cfg.LoginRateLimit,
+		Debug:              cfg.Debug,
+		MaintenanceMode:    cfg.MaintenanceMode,
+		MessageMaxAge:      cfg.MessageMaxAge,
+		QueueMaxAge:        cfg.QueueMaxAge,
+		SessionIdleTimeout: cfg.SessionIdleTimeout,
+	}
+}
+
+func TestBadSettingStopsStartup(t *testing.T) {
+	// For each setting, the first value does not parse and the others
+	// parse but are out of range.
+	tests := []struct {
+		key    string
+		values []string
+	}{
+		{key: "PORT", values: []string{"80a", "-1"}},
+		{key: "MAX_MESSAGE_SIZE", values: []string{"4k", "0", "-4096"}},
+		{key: "NEOIRC_HASHCASH_BITS", values: []string{"twenty", "-1"}},
+		{key: "LOGIN_RATE_BURST", values: []string{"five", "0", "-5"}},
+		{key: "LOGIN_RATE_LIMIT", values: []string{
+			"fast", "0", "-1", "NaN", "Inf", "-Inf",
+		}},
+		{key: "DEBUG", values: []string{"yes"}},
+		{key: "MAINTENANCE_MODE", values: []string{"on"}},
+		{key: "MESSAGE_MAX_AGE", values: []string{"30d", "0", "-1h"}},
+		{key: "QUEUE_MAX_AGE", values: []string{"720", "0s", "-24h"}},
+		{key: "SESSION_IDLE_TIMEOUT", values: []string{"a month", "0", "-1m"}},
+	}
+
+	for _, test := range tests {
+		for _, value := range test.values {
+			t.Run(test.key+"="+value, func(t *testing.T) {
+				t.Setenv(test.key, value)
+
+				_, err := loadConfig(t)
+				if err == nil {
+					t.Fatalf("%s=%q: got no error", test.key, value)
+				}
+
+				msg := err.Error()
+				if !strings.Contains(msg, test.key) ||
+					!strings.Contains(msg, value) {
+					t.Errorf("error %q does not name %s and %q",
+						msg, test.key, value)
+				}
+			})
+		}
+	}
+}
+
 func TestIRCListenAddrUnsetKeepsDefault(t *testing.T) {
 	// t.Setenv puts back whatever value was there after the test.
 	t.Setenv("IRC_LISTEN_ADDR", "")

schema/README.md

@@ -1,52 +1,58 @@
 # Message schemas
 
 This directory holds JSON Schema files (draft 2020-12) for the messages that the
-neoirc HTTP API carries. `message.json` describes the envelope every message
+neoirc HTTP API carries. `message.json` describes the fields that every message
-uses. `commands/` has files for some of the IRC commands. `numerics/` has files
+can have. `commands/` has files for some commands. `numerics/` has files for
-for some of the numeric replies. `README.md` at the repository root documents
+some of the numeric replies. A numeric reply is a server reply named by a
+three-digit number, such as `001`. `README.md` at the repository root documents
 the protocol.
 
-## The envelope
+The server can also run an IRC listener for ordinary IRC clients. The IRC
+listener sends plain IRC lines, which these files do not describe.
 
-Every message is one JSON object. These are the fields it can have:
+## Message fields
+
+Every message is one JSON object, which `message.json` calls the envelope. These
+are the fields it can have:
 
 - `command`: the IRC command name, such as `PRIVMSG`, or the name of a numeric
   reply, such as `RPL_WELCOME`. Always present.
 - `code`: the number of a numeric reply, such as `1` for `RPL_WELCOME`. Absent
   on other messages.
-- `id`: the message's UUID, assigned by the server.
+- `id`: the message's UUID, a unique ID that the server assigns.
 - `from`: the sender's nick, or the server name on a server message.
 - `to`: the target, such as a channel name starting with `#` or a nick.
-- `params`: other parameters, in order, as an array of strings. `KICK` events
+- `params`: an array of strings with the message's other parameters, in order.
-  and many numeric replies have it. The server ignores `params` sent by a
+  `KICK` events and many numeric replies have it. The HTTP API ignores `params`
-  client.
+  sent by a client.
 - `body`: an array of strings. It is never a bare string. In a `PRIVMSG` or
   `NOTICE`, each string is one line of text.
-- `ts`: when the server stored the message, as an RFC 3339 time in UTC, such as
+- `ts`: the time the server stored the message. It is an RFC 3339 time in UTC,
-  `2026-10-27T12:00:00.123Z`.
+  such as `2026-10-27T12:00:00.123Z`.
 - `meta`: an object of extra data, such as a hashcash stamp in `meta.hashcash`.
   A hashcash stamp is a short string that takes a computer some work to make. A
-  channel with mode `+H` needs one in every `PRIVMSG`. The server relays the
+  `PRIVMSG` to a channel with mode `+H` needs one. The HTTP API relays the
   `meta` of a `PRIVMSG` or `NOTICE` unchanged. It drops the `meta` of every
   other command.
 
-A `PRIVMSG` as the IRC listener sends it, and as the HTTP API sends it without
+Here is one `PRIVMSG` as the IRC listener sends it and as the HTTP API sends it.
-`id`, `ts` and `meta`:
+The JSON leaves out `id`, `ts` and `meta`:
 
 ```
 IRC:  :alice!alice@* PRIVMSG #general :hello world
 JSON: {"command": "PRIVMSG", "from": "alice", "to": "#general", "body": ["hello world"]}
 ```
 
-A numeric reply has its name in `command` and its number in `code`. This `353`
+In the JSON, a numeric reply has its name in `command` and its number in `code`.
-reply lists the members of `#general`, again without `id`, `ts` and `meta`:
+This `353` reply lists the members of `#general`. The JSON again leaves out
+`id`, `ts` and `meta`:
 
 ```
 {"command": "RPL_NAMREPLY", "code": 353, "from": "neoirc", "to": "alice",
  "params": ["=", "#general"], "body": ["@op1!op1@host1 alice!alice@host2"]}
 ```
 
-A `body` with two strings is a two-line message:
+A `PRIVMSG` whose `body` has two strings is a two-line message:
 
 ```
 {"command": "PRIVMSG", "to": "#general", "body": ["line one", "line two"]}
@@ -57,7 +63,8 @@ A `body` with two strings is a two-line message:
 Commands, in `commands/`:
 
 - `PRIVMSG.json`: a message to a channel or a user.
-- `NOTICE.json`: a notice. A client must not answer a notice automatically.
+- `NOTICE.json`: a notice, which is a message that a client must not answer
+  automatically.
 - `JOIN.json`: a user joined a channel.
 - `PART.json`: a user left a channel.
 - `QUIT.json`: a user left the server.
@@ -68,13 +75,13 @@ Commands, in `commands/`:
 - `PING.json`: a check that the server still answers.
 - `PONG.json`: the answer to a `PING`.
 - `PUBKEY.json`: an announcement of a user's public signing key. The server has
-  no such command. It answers a `PUBKEY` with `ERR_UNKNOWNCOMMAND` (421).
+  no such command. It answers a `PUBKEY` with `ERR_UNKNOWNCOMMAND` (`421`).
 
 Numeric replies, in `numerics/`:
 
 - `001.json`: `RPL_WELCOME`, which welcomes a new user.
 - `002.json`: `RPL_YOURHOST`, the server's name and version.
-- `003.json`: `RPL_CREATED`, the date the server started.
+- `003.json`: `RPL_CREATED`, which says when the server was created.
 - `004.json`: `RPL_MYINFO`, the server's version and its lists of modes.
 - `322.json`: `RPL_LIST`, one channel in the answer to `LIST`.
 - `323.json`: `RPL_LISTEND`, the end of the answer to `LIST`.
@@ -90,67 +97,70 @@ Numeric replies, in `numerics/`:
 - `442.json`: `ERR_NOTONCHANNEL`, the user is not on that channel.
 - `482.json`: `ERR_CHANOPRIVSNEEDED`, the user is not a channel operator.
 
-## Where the files differ from the server
+## Where the files differ from the HTTP API
 
-Where a schema file and the server disagree, the server is right:
+Where a schema file and the HTTP API disagree, the HTTP API is right:
 
-- `message.json` and the numeric files put the three-digit code in `command` and
+- `message.json` and the files in `numerics/` put the three-digit code in
-  have no `code` field. The server puts the reply's name in `command` and its
+  `command`. They have no `code` field. The HTTP API puts the reply's name in
-  number in `code`.
+  `command` and its number in `code`.
-- `message.json` allows an object as `body`. The server reads only arrays of
+- `message.json` allows an object as `body`. The HTTP API reads only arrays of
-  strings. A `PRIVMSG` with an object gets `ERR_NOTEXTTOSEND` (412).
+  strings. A `PRIVMSG` with an object as `body` gets `ERR_NOTEXTTOSEND` (`412`).
 - `message.json` says `to` is a channel or a nick. A `WALLOPS` message has `*`
   there.
-- `message.json` allows `meta` on every message. The server keeps `meta` only on
+- `message.json` allows `meta` on every message. The HTTP API keeps a client's
-  a `PRIVMSG` or `NOTICE`.
+  `meta` only on a `PRIVMSG` or `NOTICE`.
 - `message.json` describes signature fields in `meta`. The server never checks a
   signature.
-- `message.json` does not describe `meta.hashcash`. The server reads it in a
+- `message.json` does not describe `meta.hashcash`. The HTTP API reads it in a
   `PRIVMSG` to a channel with mode `+H`.
 - `JOIN.json` has no `body`. A client's `JOIN` can carry the channel key in
-  `body`. When a user joins, the server's `JOIN` event repeats the channel name
+  `body`. When a user joins, the `JOIN` event repeats the channel name in
-  there.
+  `body`.
 - `JOIN.json` allows a channel name of any length. The server allows at most 63
   characters after the `#`. It answers a longer name with `ERR_NOSUCHCHANNEL`
-  (403).
+  (`403`).
-- `KICK.json` puts the kicked nick in `params`. The server reads a client's
+- `KICK.json` puts the kicked nick in `params`. The HTTP API reads a client's
   `KICK` from `body`: the nick, then an optional reason.
-- `MODE.json` puts the mode change in `params`. The server uses `body` instead.
+- `MODE.json` puts the mode change in `params`. The HTTP API uses `body`
-  A client sends the change and any value as separate strings, such as `"+o"`
+  instead. A client sends the change and any value as separate strings, such as
-  and `"bob"`. The server's `MODE` event has one string such as `"+o bob"`, or
+  `"+o"` and `"bob"`. In a `MODE` event, `body` holds the change as one string,
-  the change and its value as two strings, such as `"+k"` and `"secret"`.
+  such as `"+o bob"`, or as two strings, such as `"+k"` and `"secret"`.
-- `NOTICE.json` allows `*` as `to`. The server answers that with
+- `NOTICE.json` allows `*` as `to`. The server answers a `NOTICE` to `*` with
-  `ERR_NOSUCHNICK` (401).
+  `ERR_NOSUCHNICK` (`401`).
 - `NOTICE.json` has an example notice from the server to `*`. The server sends
   no such notice.
-- `PING.json` and `PONG.json` describe a token that the `PONG` repeats. The
+- `PING.json` and `PONG.json` describe a token that the `PONG` repeats. The HTTP
-  server ignores the `body` of a `PING`. It answers the HTTP request itself with
+  API ignores the `body` of a `PING`. Its answer is the HTTP response
   `{"command": "PONG", "from": "<server name>"}`.
 - `PING.json` and `PONG.json` also describe messages between servers. The server
   does not connect to other IRC servers.
 - `PUBKEY.json` describes a command the server does not have.
-- `QUIT.json` says only the server sends `QUIT`. A client can send it too, to
+- `QUIT.json` says that `QUIT` comes only from the server. A client can send it
-  end its session. The client's `QUIT` can carry a reason in `body`.
+  too, to end its session. A client's `QUIT` can carry a reason in `body`.
-- `TOPIC.json` says a `TOPIC` without a `body` queries the topic. Over the HTTP
+- `TOPIC.json` says a `TOPIC` without a `body` queries the topic. The HTTP API
-  API a `TOPIC` without a `body` gets `ERR_NEEDMOREPARAMS` (461).
+  answers such a `TOPIC` with `ERR_NEEDMOREPARAMS` (`461`).
-- `TOPIC.json` says an empty array clears the topic. The server answers `[]`
+- `TOPIC.json` says an empty array clears the topic. The HTTP API answers `[]`
-  with `ERR_NEEDMOREPARAMS` (461). A `body` of `[""]` clears the topic.
+  with `ERR_NEEDMOREPARAMS` (`461`). A `body` of `[""]` clears the topic.
-- `003.json` describes the server's creation date. The server sends the date it
+- `003.json` describes the server's creation date. The HTTP API sends the date
-  last started.
+  the server last started.
-- `004.json` has example mode lists. The server sends an empty string as the
+- `004.json` has example mode lists. The HTTP API sends an empty string as the
   user modes and `ikmnostl` as the channel modes.
-- `322.json` says `LIST` gets one reply per channel. The server leaves out each
+- `322.json` says `LIST` gets one reply per channel. The server leaves out a
-  secret channel that the user is not on.
+  secret channel, one with mode `+s`, unless the user is on it.
-- `353.json` says `body` lists nicks. Over the HTTP API the server lists
+- `332.json` says `RPL_TOPIC` answers a `TOPIC` query. The HTTP API has no such
-  `nick!user@host` in place of each nick, such as `@op1!op1@host1`.
+  query. It sends `RPL_TOPIC` after a client sets the topic, and after a `JOIN`
+  to a channel that has one.
+- `353.json` says `body` lists nicks. The HTTP API lists `nick!user@host` in
+  place of each nick, such as `@op1!op1@host1`.
 - `353.json` says the first parameter marks a channel as public, private or
   secret. The server always sends `=`, the mark for a public channel.
-- `376.json` gives the text as `End of /MOTD command`. The server adds a full
+- `376.json` gives the text as `End of /MOTD command`. The HTTP API adds a full
   stop.
-- `401.json` gives the text as `No such nick/channel`. For a `PRIVMSG` or
+- `401.json` gives the text as `No such nick/channel`. The server sends
-  `NOTICE` to an unknown nick, the server sends `No such nick`.
+  `No such nick` in answer to a `PRIVMSG` or `NOTICE` to an unknown nick.
-- `433.json` has an example with `*` as `to`. Over the HTTP API the server sends
+- `433.json` has an example with `*` as `to`. The HTTP API sends `433` only in
-  `433` only in answer to a `NICK`, with the user's nick as `to`.
+  answer to a `NICK`, with the user's nick as `to`.
 
-The server also accepts some messages that the files do not allow, such as a
+The HTTP API also accepts some messages that the files do not allow, such as a
-channel name without its `#`.
+`JOIN` whose `to` has no `#`.