Don't fetch suggestions after copy-earlier-word

Like {up,down}-line-or-beginning-search, this widget relies on
`$LASTWIDGET` being set to function correctly on subsequent invocations.

When asynchronous suggestions are enabled, and the widget triggers a
suggestion to be fetched, `autosuggest-suggest` will be called and
$LASTWIDGET will be set to it.

Makefile

@@ -1,7 +1,6 @@
 SRC_DIR    := ./src
 
 SRC_FILES := \
-	$(SRC_DIR)/setup.zsh \
 	$(SRC_DIR)/config.zsh \
 	$(SRC_DIR)/util.zsh \
 	$(SRC_DIR)/bind.zsh \

README.md

@@ -2,7 +2,7 @@
 
 _[Fish](http://fishshell.com/)-like fast/unobtrusive autosuggestions for zsh._
 
-It suggests commands as you type, based on command history.
+It suggests commands as you type.
 
 Requirements: Zsh v4.3.11 or later
 
@@ -34,15 +34,26 @@ You may want to override the default global config variables. Default values of
 
 ### Suggestion Highlight Style
 
-Set `ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE` to configure the style that the suggestion is shown with. The default is `fg=8`.
+Set `ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE` to configure the style that the suggestion is shown with. The default is `fg=8`, which will set the foreground color to color 8 from the 256-color palette. If your terminal only supports 8 colors, you will need to use a number between 0 and 7.
+
+Background color can also be set, and the suggestion can be styled bold, underlined, or standout. For example, this would show suggestions with bold, underlined, pink text on a cyan background:
+
+```sh
+ZSH_AUTOSUGGEST_HIGHLIGHT_STYLE="fg=#ff00ff,bg=cyan,bold,underline"
+```
+
+For more info, read the Character Highlighting section of the zsh manual: `man zshzle` or [online](http://zsh.sourceforge.net/Doc/Release/Zsh-Line-Editor.html#Character-Highlighting).
 
 
 ### Suggestion Strategy
 
-`ZSH_AUTOSUGGEST_STRATEGY` is an array that specifies how suggestions should be generated. The strategies in the array are tried successively until a suggestion is found. There are currently two built-in strategies to choose from:
+`ZSH_AUTOSUGGEST_STRATEGY` is an array that specifies how suggestions should be generated. The strategies in the array are tried successively until a suggestion is found. There are currently three built-in strategies to choose from:
 
 - `history`: Chooses the most recent match from history.
 - `match_prev_cmd`: Like `history`, but chooses the most recent match whose preceding history item matches the most recently executed command ([more info](src/strategies/match_prev_cmd.zsh)). Note that this strategy won't work as expected with ZSH options that don't preserve the history order such as `HIST_IGNORE_ALL_DUPS` or `HIST_EXPIRE_DUPS_FIRST`.
+- `completion`: (experimental) Chooses a suggestion based on what tab-completion would suggest. (requires `zpty` module)
+
+For example, setting `ZSH_AUTOSUGGEST_STRATEGY=(history completion)` will first try to find a suggestion from your history, but, if it can't find a match, will find a suggestion from the completion engine.
 
 
 ### Widget Mapping

spec/async_spec.rb

@@ -27,6 +27,29 @@ context 'with asynchronous suggestions enabled' do
     end
   end
 
+  describe '`copy-earlier-word`' do
+    let(:before_sourcing) do
+      -> do
+        session.
+          run_command('autoload -Uz copy-earlier-word').
+          run_command('zle -N copy-earlier-word').
+          run_command('bindkey "^N" copy-earlier-word')
+      end
+    end
+
+    it 'should cycle through previous words in the buffer' do
+      session.clear_screen
+      session.send_string('foo bar baz')
+      sleep 0.5
+      session.send_keys('C-n')
+      wait_for { session.content }.to eq('foo bar bazbaz')
+      session.send_keys('C-n')
+      wait_for { session.content }.to eq('foo bar bazbar')
+      session.send_keys('C-n')
+      wait_for { session.content }.to eq('foo bar bazfoo')
+    end
+  end
+
   describe 'pressing ^C after fetching a suggestion' do
     before do
       skip 'Workaround does not work below v5.0.8' if session.zsh_version < Gem::Version.new('5.0.8')
@@ -34,9 +57,9 @@ context 'with asynchronous suggestions enabled' do
 
     it 'terminates the prompt and begins a new one' do
       session.send_keys('e')
-      sleep 0.1
+      sleep 0.5
       session.send_keys('C-c')
-      sleep 0.1
+      sleep 0.5
       session.send_keys('echo')
 
       wait_for { session.content }.to eq("e\necho")

spec/integrations/bracketed_paste_magic_spec.rb

@@ -24,4 +24,20 @@ describe 'pasting using bracketed-paste-magic' do
       end
     end
   end
+
+  context 'with `bracketed-paste` added to the list of widgets that clear the suggestion' do
+    let(:options) { ['ZSH_AUTOSUGGEST_CLEAR_WIDGETS+=(bracketed-paste)'] }
+
+    it 'does not retain an old suggestion' do
+      with_history ('echo foo') do
+        session.send_string('echo ')
+        wait_for { session.content }.to eq('echo foo')
+        session.paste_string('bar')
+        wait_for { session.content }.to eq('echo bar')
+        session.send_keys('C-a') # Any cursor movement works
+        sleep 1
+        expect(session.content).to eq('echo bar')
+      end
+    end
+  end
 end

spec/integrations/client_zpty_spec.rb

@@ -0,0 +1,14 @@
+describe 'a running zpty command' do
+  let(:before_sourcing) { -> { session.run_command('zmodload zsh/zpty && zpty -b kitty cat') } }
+
+  context 'when using `completion` strategy' do
+    let(:options) { ["ZSH_AUTOSUGGEST_STRATEGY=completion"] }
+
+    it 'is not affected' do
+      session.send_keys('a').send_keys('C-h')
+      session.run_command('zpty -t kitty; echo $?')
+
+      wait_for { session.content }.to end_with("\n0")
+    end
+  end
+end

spec/spec_helper.rb

@@ -11,8 +11,7 @@ RSpec.shared_context 'terminal session' do
 
   around do |example|
     before_sourcing.call
-    session.run_command(options.join('; '))
-    session.run_command('source zsh-autosuggestions.zsh')
+    session.run_command(['source zsh-autosuggestions.zsh', *options].join('; '))
     after_sourcing.call
     session.clear_screen
 

spec/strategies/completion_spec.rb

@@ -0,0 +1,26 @@
+describe 'the `completion` suggestion strategy' do
+  let(:options) { ['ZSH_AUTOSUGGEST_STRATEGY=completion'] }
+  let(:before_sourcing) do
+    -> do
+      session.
+        run_command('autoload compinit && compinit').
+        run_command('_foo() { compadd bar }').
+        run_command('compdef _foo baz')
+    end
+  end
+
+  it 'suggests the first completion result' do
+    session.send_string('baz ')
+    wait_for { session.content }.to eq('baz bar')
+  end
+
+  context 'when async mode is enabled' do
+    let(:options) { ['ZSH_AUTOSUGGEST_USE_ASYNC=true', 'ZSH_AUTOSUGGEST_STRATEGY=completion'] }
+
+    it 'suggests the first completion result' do
+      session.send_string('baz ')
+      wait_for { session.content }.to eq('baz bar')
+    end
+  end
+end
+

src/config.zsh

@@ -35,6 +35,7 @@ typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
 		up-line-or-history
 		down-line-or-history
 		accept-line
+		copy-earlier-word
 	)
 }
 
@@ -85,3 +86,7 @@ typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
 		yank-pop
 	)
 }
+
+# Pty name for capturing completions for completion suggestion strategy
+(( ! ${+ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME} )) &&
+typeset -g ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME=zsh_autosuggest_completion_pty

src/fetch.zsh

@@ -18,7 +18,10 @@ _zsh_autosuggest_fetch_suggestion() {
 		# Try to get a suggestion from this strategy
 		_zsh_autosuggest_strategy_$strategy "$1"
 
-		# Break once we've found a suggestion
+		# Ensure the suggestion matches the prefix
+		[[ "$suggestion" != "$1"* ]] && unset suggestion
+
+		# Break once we've found a valid suggestion
 		[[ -n "$suggestion" ]] && break
 	done
 }

src/setup.zsh

@@ -1,10 +0,0 @@
-
-#--------------------------------------------------------------------#
-# Setup                                                              #
-#--------------------------------------------------------------------#
-
-# Precmd hooks for initializing the library and starting pty's
-autoload -Uz add-zsh-hook
-
-# Asynchronous suggestions are generated in a pty
-zmodload zsh/zpty

src/start.zsh

@@ -19,4 +19,5 @@ _zsh_autosuggest_start() {
 }
 
 # Start the autosuggestion widgets on the next precmd
+autoload -Uz add-zsh-hook
 add-zsh-hook precmd _zsh_autosuggest_start

src/strategies/completion.zsh

@@ -0,0 +1,109 @@
+
+#--------------------------------------------------------------------#
+# Completion Suggestion Strategy                                     #
+#--------------------------------------------------------------------#
+# Fetches a suggestion from the completion engine
+#
+
+_zsh_autosuggest_capture_postcompletion() {
+	# Always insert the first completion into the buffer
+	compstate[insert]=1
+
+	# Don't list completions
+	unset compstate[list]
+}
+
+_zsh_autosuggest_capture_completion_widget() {
+	local -a +h comppostfuncs
+	comppostfuncs=(_zsh_autosuggest_capture_postcompletion)
+
+	# Only capture completions at the end of the buffer
+	CURSOR=$#BUFFER
+
+	# Run the original widget wrapping `.complete-word` so we don't
+	# recursively try to fetch suggestions, since our pty is forked
+	# after autosuggestions is initialized.
+	zle -- ${(k)widgets[(r)completion:.complete-word:_main_complete]}
+
+	# The completion has been added, print the buffer as the suggestion
+	echo -nE - $'\0'$BUFFER$'\0'
+}
+
+zle -N autosuggest-capture-completion _zsh_autosuggest_capture_completion_widget
+
+_zsh_autosuggest_capture_setup() {
+	# There is a bug in zpty module in older zsh versions by which a
+	# zpty that exits will kill all zpty processes that were forked
+	# before it. Here we set up a zsh exit hook to SIGKILL the zpty
+	# process immediately, before it has a chance to kill any other
+	# zpty processes.
+	if ! is-at-least 5.4; then
+		zshexit() {
+			kill -KILL $$
+			sleep 1 # Block for long enough for the signal to come through
+		}
+	fi
+
+	# Try to avoid any suggestions that wouldn't match the prefix
+	zstyle ':completion:*' matcher-list ''
+	zstyle ':completion:*' path-completion false
+	zstyle ':completion:*' max-errors 0 not-numeric
+
+	bindkey '^I' autosuggest-capture-completion
+}
+
+_zsh_autosuggest_capture_completion_sync() {
+	_zsh_autosuggest_capture_setup
+
+	zle autosuggest-capture-completion
+}
+
+_zsh_autosuggest_capture_completion_async() {
+	_zsh_autosuggest_capture_setup
+
+	zmodload zsh/parameter 2>/dev/null || return # For `$functions`
+
+	# Make vared completion work as if for a normal command line
+	# https://stackoverflow.com/a/7057118/154703
+	autoload +X _complete
+	functions[_original_complete]=$functions[_complete]
+	_complete () {
+		unset 'compstate[vared]'
+		_original_complete "$@"
+	}
+
+	# Open zle with buffer set so we can capture completions for it
+	vared 1
+}
+
+_zsh_autosuggest_strategy_completion() {
+	typeset -g suggestion
+	local line REPLY
+
+	# Exit if we don't have completions
+	whence compdef >/dev/null || return
+
+	# Exit if we don't have zpty
+	zmodload zsh/zpty 2>/dev/null || return
+
+	# Zle will be inactive if we are in async mode
+	if zle; then
+		zpty $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME _zsh_autosuggest_capture_completion_sync
+	else
+		zpty $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME _zsh_autosuggest_capture_completion_async "\$1"
+		zpty -w $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME $'\t'
+	fi
+
+	{
+		# The completion result is surrounded by null bytes, so read the
+		# content between the first two null bytes.
+		zpty -r $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME line '*'$'\0''*'$'\0'
+
+		# On older versions of zsh, we sometimes get extra bytes after the
+		# second null byte, so trim those off the end
+		suggestion="${${${(M)line:#*$'\0'*$'\0'*}#*$'\0'}%%$'\0'*}"
+	} always {
+		# Destroy the pty
+		zpty -d $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME
+	}
+}

src/widgets.zsh

@@ -85,7 +85,7 @@ _zsh_autosuggest_modify() {
 
 	# Get a new suggestion if the buffer is not empty after modification
 	if (( $#BUFFER > 0 )); then
-		if (( ! ${+ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE} )) || (( $#BUFFER <= $ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE )); then
+		if [[ -z "$ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE" ]] || (( $#BUFFER <= $ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE )); then
 			_zsh_autosuggest_fetch
 		fi
 	fi

zsh-autosuggestions.zsh

@@ -25,16 +25,6 @@
 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 # OTHER DEALINGS IN THE SOFTWARE.
 
-#--------------------------------------------------------------------#
-# Setup                                                              #
-#--------------------------------------------------------------------#
-
-# Precmd hooks for initializing the library and starting pty's
-autoload -Uz add-zsh-hook
-
-# Asynchronous suggestions are generated in a pty
-zmodload zsh/zpty
-
 #--------------------------------------------------------------------#
 # Global Configuration Variables                                     #
 #--------------------------------------------------------------------#
@@ -71,6 +61,7 @@ typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
 		up-line-or-history
 		down-line-or-history
 		accept-line
+		copy-earlier-word
 	)
 }
 
@@ -122,6 +113,10 @@ typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
 	)
 }
 
+# Pty name for capturing completions for completion suggestion strategy
+(( ! ${+ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME} )) &&
+typeset -g ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME=zsh_autosuggest_completion_pty
+
 #--------------------------------------------------------------------#
 # Utility Functions                                                  #
 #--------------------------------------------------------------------#
@@ -352,7 +347,7 @@ _zsh_autosuggest_modify() {
 
 	# Get a new suggestion if the buffer is not empty after modification
 	if (( $#BUFFER > 0 )); then
-		if (( ! ${+ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE} )) || (( $#BUFFER <= $ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE )); then
+		if [[ -z "$ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE" ]] || (( $#BUFFER <= $ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE )); then
 			_zsh_autosuggest_fetch
 		fi
 	fi
@@ -486,6 +481,115 @@ _zsh_autosuggest_partial_accept() {
 	zle -N autosuggest-toggle _zsh_autosuggest_widget_toggle
 }
 
+#--------------------------------------------------------------------#
+# Completion Suggestion Strategy                                     #
+#--------------------------------------------------------------------#
+# Fetches a suggestion from the completion engine
+#
+
+_zsh_autosuggest_capture_postcompletion() {
+	# Always insert the first completion into the buffer
+	compstate[insert]=1
+
+	# Don't list completions
+	unset compstate[list]
+}
+
+_zsh_autosuggest_capture_completion_widget() {
+	local -a +h comppostfuncs
+	comppostfuncs=(_zsh_autosuggest_capture_postcompletion)
+
+	# Only capture completions at the end of the buffer
+	CURSOR=$#BUFFER
+
+	# Run the original widget wrapping `.complete-word` so we don't
+	# recursively try to fetch suggestions, since our pty is forked
+	# after autosuggestions is initialized.
+	zle -- ${(k)widgets[(r)completion:.complete-word:_main_complete]}
+
+	# The completion has been added, print the buffer as the suggestion
+	echo -nE - $'\0'$BUFFER$'\0'
+}
+
+zle -N autosuggest-capture-completion _zsh_autosuggest_capture_completion_widget
+
+_zsh_autosuggest_capture_setup() {
+	# There is a bug in zpty module in older zsh versions by which a
+	# zpty that exits will kill all zpty processes that were forked
+	# before it. Here we set up a zsh exit hook to SIGKILL the zpty
+	# process immediately, before it has a chance to kill any other
+	# zpty processes.
+	if ! is-at-least 5.4; then
+		zshexit() {
+			kill -KILL $$
+			sleep 1 # Block for long enough for the signal to come through
+		}
+	fi
+
+	# Try to avoid any suggestions that wouldn't match the prefix
+	zstyle ':completion:*' matcher-list ''
+	zstyle ':completion:*' path-completion false
+	zstyle ':completion:*' max-errors 0 not-numeric
+
+	bindkey '^I' autosuggest-capture-completion
+}
+
+_zsh_autosuggest_capture_completion_sync() {
+	_zsh_autosuggest_capture_setup
+
+	zle autosuggest-capture-completion
+}
+
+_zsh_autosuggest_capture_completion_async() {
+	_zsh_autosuggest_capture_setup
+
+	zmodload zsh/parameter 2>/dev/null || return # For `$functions`
+
+	# Make vared completion work as if for a normal command line
+	# https://stackoverflow.com/a/7057118/154703
+	autoload +X _complete
+	functions[_original_complete]=$functions[_complete]
+	_complete () {
+		unset 'compstate[vared]'
+		_original_complete "$@"
+	}
+
+	# Open zle with buffer set so we can capture completions for it
+	vared 1
+}
+
+_zsh_autosuggest_strategy_completion() {
+	typeset -g suggestion
+	local line REPLY
+
+	# Exit if we don't have completions
+	whence compdef >/dev/null || return
+
+	# Exit if we don't have zpty
+	zmodload zsh/zpty 2>/dev/null || return
+
+	# Zle will be inactive if we are in async mode
+	if zle; then
+		zpty $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME _zsh_autosuggest_capture_completion_sync
+	else
+		zpty $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME _zsh_autosuggest_capture_completion_async "\$1"
+		zpty -w $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME $'\t'
+	fi
+
+	{
+		# The completion result is surrounded by null bytes, so read the
+		# content between the first two null bytes.
+		zpty -r $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME line '*'$'\0''*'$'\0'
+
+		# On older versions of zsh, we sometimes get extra bytes after the
+		# second null byte, so trim those off the end
+		suggestion="${${${(M)line:#*$'\0'*$'\0'*}#*$'\0'}%%$'\0'*}"
+	} always {
+		# Destroy the pty
+		zpty -d $ZSH_AUTOSUGGEST_COMPLETIONS_PTY_NAME
+	}
+}
+
 #--------------------------------------------------------------------#
 # History Suggestion Strategy                                        #
 #--------------------------------------------------------------------#
@@ -589,7 +693,10 @@ _zsh_autosuggest_fetch_suggestion() {
 		# Try to get a suggestion from this strategy
 		_zsh_autosuggest_strategy_$strategy "$1"
 
-		# Break once we've found a suggestion
+		# Ensure the suggestion matches the prefix
+		[[ "$suggestion" != "$1"* ]] && unset suggestion
+
+		# Break once we've found a valid suggestion
 		[[ -n "$suggestion" ]] && break
 	done
 }
@@ -683,4 +790,5 @@ _zsh_autosuggest_start() {
 }
 
 # Start the autosuggestion widgets on the next precmd
+autoload -Uz add-zsh-hook
 add-zsh-hook precmd _zsh_autosuggest_start