Add bash shell completion support

docs/cli-reference.md

@@ -478,9 +478,10 @@ Update fetch binary in place. Use with `--dry-run` to check for updates without
 
 ### `--complete SHELL`
 
-Output shell completion scripts. Values: `fish`, `zsh`.
+Output shell completion scripts. Values: `bash`, `fish`, `zsh`.
 
 ```sh
+echo 'eval "$(fetch --complete bash)"' >> ~/.bashrc
 fetch --complete zsh > ~/.zshrc.d/_fetch
 fetch --complete fish > ~/.config/fish/completions/fetch.fish
 ```

docs/getting-started.md

@@ -126,6 +126,9 @@ auto-update = true
 Generate shell completion scripts:
 
 ```sh
+# Bash
+echo 'eval "$(fetch --complete bash)"' >> ~/.bashrc
+
 # Zsh
 fetch --complete zsh > ~/.zshrc.d/fetch-completion.zsh
 

install.sh

@@ -145,6 +145,13 @@ info "fetch successfully installed to '${DIM}${INSTALL_DIR}/fetch${RESET}'"
 
 # Optionally install completions.
 case "$SHELL" in
+  */bash)
+    COMPLETION_CMD='eval "$(fetch --complete=bash)"'
+    if ! grep -qF "$COMPLETION_CMD" "$HOME/.bashrc" 2>/dev/null; then
+      printf "\n# fetch completions\n${COMPLETION_CMD}\n" >> "$HOME/.bashrc"
+      info "completions appended to '${DIM}${HOME}/.bashrc${RESET}'"
+    fi
+    ;;
   */fish)
     mkdir -p "$HOME/.config/fish/completions"
     echo "fetch --complete=fish | source" > "$HOME/.config/fish/completions/fetch.fish"

internal/cli/app.go

@@ -240,6 +240,20 @@ func (a *App) CLI() *CLI {
 					return a.Cfg.ParseCert(value)
 				},
 			},
+			{
+				Short:       "",
+				Long:        "clobber",
+				Args:        "",
+				Description: "Overwrite existing output file",
+				Default:     "",
+				IsSet: func() bool {
+					return a.Clobber
+				},
+				Fn: func(value string) error {
+					a.Clobber = true
+					return nil
+				},
+			},
 			{
 				Short:       "",
 				Long:        "color",
@@ -268,27 +282,14 @@ func (a *App) CLI() *CLI {
 					return a.Cfg.ParseColor(value)
 				},
 			},
-			{
-				Short:       "",
-				Long:        "clobber",
-				Args:        "",
-				Description: "Overwrite existing output file",
-				Default:     "",
-				IsSet: func() bool {
-					return a.Clobber
-				},
-				Fn: func(value string) error {
-					a.Clobber = true
-					return nil
-				},
-			},
 			{
 				Short:       "",
 				Long:        "complete",
 				Args:        "SHELL",
 				Description: "Output shell completion",
 				Default:     "",
 				Values: []core.KeyVal[string]{
+					{Key: "bash"},
 					{Key: "fish"},
 					{Key: "zsh"},
 				},
@@ -847,6 +848,19 @@ func (a *App) CLI() *CLI {
 					return nil
 				},
 			},
+			{
+				Short:       "S",
+				Long:        "session",
+				Args:        "NAME",
+				Description: "Use a named session for cookies",
+				Default:     "",
+				IsSet: func() bool {
+					return a.Cfg.Session != nil
+				},
+				Fn: func(value string) error {
+					return a.Cfg.ParseSession(value)
+				},
+			},
 			{
 				Short:       "s",
 				Long:        "silent",
@@ -862,19 +876,6 @@ func (a *App) CLI() *CLI {
 					return nil
 				},
 			},
-			{
-				Short:       "S",
-				Long:        "session",
-				Args:        "NAME",
-				Description: "Use a named session for cookies",
-				Default:     "",
-				IsSet: func() bool {
-					return a.Cfg.Session != nil
-				},
-				Fn: func(value string) error {
-					return a.Cfg.ParseSession(value)
-				},
-			},
 			{
 				Short:       "t",
 				Long:        "timeout",

internal/cli/cli_test.go

@@ -8,6 +8,21 @@ import (
 	"github.com/ryanfowler/fetch/internal/core"
 )
 
+func TestFlagsAlphabeticalOrder(t *testing.T) {
+	app, err := Parse(nil)
+	if err != nil {
+		t.Fatalf("unable to parse cli: %s", err.Error())
+	}
+	cli := app.CLI()
+	for i := 1; i < len(cli.Flags); i++ {
+		prev := cli.Flags[i-1].Long
+		curr := cli.Flags[i].Long
+		if curr < prev {
+			t.Errorf("flags out of alphabetical order: %q should come before %q", curr, prev)
+		}
+	}
+}
+
 func TestCLI(t *testing.T) {
 	app, err := Parse(nil)
 	if err != nil {

internal/complete/complete_test.go

@@ -7,6 +7,76 @@ import (
 	"github.com/ryanfowler/fetch/internal/cli"
 )
 
+func TestCompleteBash(t *testing.T) {
+	var app cli.App
+	flags := app.CLI().Flags
+	_, long := getFlagMaps(flags)
+
+	tests := []struct {
+		name  string
+		shell Shell
+		args  []string
+		exp   string
+	}{
+		{
+			name:  "should return nothing when no args",
+			shell: Bash{},
+			args:  nil,
+			exp:   "",
+		},
+		{
+			name:  "should return nothing when only arg is command",
+			shell: Bash{},
+			args:  []string{"fetch"},
+			exp:   "",
+		},
+		{
+			name:  "should complete color flag",
+			shell: Bash{},
+			args:  []string{"fetch", "--col"},
+			exp:   "--color \n",
+		},
+		{
+			name:  "should complete color value",
+			shell: Bash{},
+			args:  []string{"fetch", "--color", ""},
+			exp: func() string {
+				var sb strings.Builder
+				for _, kv := range long["color"].Values {
+					sb.WriteString(kv.Key)
+					sb.WriteString(" \n")
+				}
+				return sb.String()
+			}(),
+		},
+		{
+			name:  "should complete color value with prefix",
+			shell: Bash{},
+			args:  []string{"fetch", "--color", "o"},
+			exp: func() string {
+				var sb strings.Builder
+				for _, kv := range long["color"].Values {
+					if !strings.HasPrefix(kv.Key, "o") {
+						continue
+					}
+					sb.WriteString(kv.Key)
+					sb.WriteString(" \n")
+				}
+				return sb.String()
+			}(),
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			res := Complete(test.shell, test.args)
+			if res != test.exp {
+				t.Fatalf("Unexpected result:\n%s", res)
+			}
+		})
+	}
+}
+
 func TestCompleteFish(t *testing.T) {
 	var app cli.App
 	flags := app.CLI().Flags

internal/complete/shells.go

@@ -17,6 +17,8 @@ type Shell interface {
 // nil is returned.
 func GetShell(name string) Shell {
 	switch name {
+	case "bash":
+		return Bash{}
 	case "fish":
 		return Fish{}
 	case "zsh":
@@ -26,6 +28,36 @@ func GetShell(name string) Shell {
 	}
 }
 
+type Bash struct{}
+
+func (b Bash) Name() string {
+	return "bash"
+}
+
+func (b Bash) Register() string {
+	return `_fetch_complete() {
+  local cur prev_tokens
+  cur="${COMP_WORDS[COMP_CWORD]}"
+  prev_tokens=("${COMP_WORDS[@]:0:COMP_CWORD}")
+  local IFS=$'\n'
+  COMPREPLY=($(fetch --complete=bash -- "${prev_tokens[@]}" "$cur"))
+  IFS=$' \t\n'
+}
+complete -o nosort -o nospace -F _fetch_complete fetch`
+}
+
+func (b Bash) Complete(vals []core.KeyVal[string]) string {
+	var sb strings.Builder
+	for _, kv := range vals {
+		sb.WriteString(kv.Key)
+		if !strings.HasSuffix(kv.Key, "/") && !strings.HasSuffix(kv.Key, "=") {
+			sb.WriteByte(' ')
+		}
+		sb.WriteByte('\n')
+	}
+	return sb.String()
+}
+
 type Fish struct{}
 
 func (f Fish) Name() string {