Fix issues with LASTWIDGET caused by async suggestions

There are a number of widgets that rely on LASTWIDGET so that they can
chain their behavior together on subsequent invocations. When a
suggestion was fetched asynchronously, the widget showing the suggestion
would overwrite LASTWIDGET and break these widgets that rely on it.
Relatively recently, a flag was added to the `zle` builtin to opt out of
setting LASTWIDGET when calling a widget. We can use that flag to avoid
setting LASTWIDGET when displaying suggestions that were fetched
asynchronously.

.circleci/config.yml

@@ -1,15 +0,0 @@
-version: 2
-jobs:
-  build:
-    parallelism: 4
-    shell: /bin/bash --login
-    docker:
-    - image: ericfreese/zsh-autosuggestions-test:latest
-    steps:
-    - checkout
-    - run:
-        name: Running tests
-        command: |
-          for v in $(grep "^[^#]" ZSH_VERSIONS | awk "(NR + $CIRCLE_NODE_INDEX) % $CIRCLE_NODE_TOTAL == 0"); do
-            TEST_ZSH_BIN=zsh-$v make test || exit 1
-          done

.github/workflows/integration.yml

@@ -0,0 +1,51 @@
+on: [push, pull_request]
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+env:
+  IMAGE_CACHE_PATH: /tmp/.image-cache
+  IMAGE_CACHE_NAME: zsh-autosuggestions-test
+jobs:
+  determine-versions:
+    runs-on: ubuntu-22.04
+    outputs:
+      versions: ${{ steps.set-versions.outputs.versions }}
+    steps:
+    - uses: actions/checkout@v3
+    - id: set-versions
+      run: |
+        echo "versions=$(
+          grep "^[^#]" ZSH_VERSIONS \
+          | sed -E 's/(^|$)/"/g' \
+          | paste -sd ',' - \
+          | sed -e 's/^/[/' -e 's/$/]/'
+        )" >> $GITHUB_OUTPUT
+  test:
+    needs: determine-versions
+    runs-on: ubuntu-22.04
+    strategy:
+      matrix:
+        version: ${{ fromJson(needs.determine-versions.outputs.versions) }}
+    steps:
+    - uses: actions/checkout@v3
+    - name: Docker image cache
+      id: image-cache
+      uses: actions/cache@v3
+      with:
+        path: ${{ env.IMAGE_CACHE_PATH }}
+        key: image-cache-${{ matrix.version }}-${{ hashFiles('Dockerfile', 'install_test_zsh.sh', 'Gemfile.lock') }}
+    - name: Load cached docker image if available
+      if: ${{ steps.image-cache.outputs.cache-hit }}
+      run: gunzip < $IMAGE_CACHE_PATH/$IMAGE_CACHE_NAME.tar.gz | docker load
+    - name: Build the docker image if necessary
+      if: ${{ !steps.image-cache.outputs.cache-hit }}
+      run: |
+        docker build --build-arg TEST_ZSH_VERSION=${{ matrix.version }} -t $IMAGE_CACHE_NAME .
+        mkdir -p $IMAGE_CACHE_PATH
+        docker save $IMAGE_CACHE_NAME | gzip > $IMAGE_CACHE_PATH/$IMAGE_CACHE_NAME.tar.gz
+    - name: Run the tests
+      run: |
+        docker run --rm \
+          -v $PWD:/zsh-autosuggestions \
+          $IMAGE_CACHE_NAME \
+          make test

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## v0.7.0
+- Enable asynchronous mode by default (#498)
+- No longer wrap user widgets starting with `autosuggest-` prefix (#496)
+- Fix a bug wrapping widgets that modify the buffer (#541)
+
+
 ## v0.6.4
 - Fix `vi-forward-char` triggering a bell when using it to accept a suggestion (#488)
 - New configuration option to skip completion suggestions when buffer matches a pattern (#487)

Dockerfile

@@ -1,5 +1,8 @@
 FROM ruby:2.5.3-alpine
 
+ARG TEST_ZSH_VERSION
+RUN : "${TEST_ZSH_VERSION:?}"
+
 RUN apk add --no-cache autoconf
 RUN apk add --no-cache libtool
 RUN apk add --no-cache libcap-dev
@@ -11,10 +14,8 @@ RUN apk add --no-cache tmux
 
 WORKDIR /zsh-autosuggestions
 
-ADD ZSH_VERSIONS /zsh-autosuggestions/ZSH_VERSIONS
-ADD install_test_zsh.sh /zsh-autosuggestions/install_test_zsh.sh
+ADD install_test_zsh.sh ./
 RUN ./install_test_zsh.sh
 
-ADD Gemfile /zsh-autosuggestions/Gemfile
-ADD Gemfile.lock /zsh-autosuggestions/Gemfile.lock
+ADD Gemfile Gemfile.lock ./
 RUN bundle install

INSTALL.md

@@ -39,7 +39,10 @@
 2. Add the plugin to the list of plugins for Oh My Zsh to load (inside `~/.zshrc`):
 
     ```sh
-    plugins=(zsh-autosuggestions)
+    plugins=( 
+        # other plugins...
+        zsh-autosuggestions
+    )
     ```
 
 3. Start a new terminal session.

LICENSE

@@ -1,5 +1,5 @@
 Copyright (c) 2013 Thiago de Arruda
-Copyright (c) 2016-2019 Eric Freese
+Copyright (c) 2016-2021 Eric Freese
 
 Permission is hereby granted, free of charge, to any person
 obtaining a copy of this software and associated documentation

README.md

@@ -79,9 +79,11 @@ Widgets that modify the buffer and are not found in any of these arrays will fet
 Set `ZSH_AUTOSUGGEST_BUFFER_MAX_SIZE` to an integer value to disable autosuggestion for large buffers. The default is unset, which means that autosuggestion will be tried for any buffer size. Recommended value is 20.
 This can be useful when pasting large amount of text in the terminal, to avoid triggering autosuggestion for strings that are too long.
 
-### Enable Asynchronous Mode
+### Asynchronous Mode
 
-As of `v0.4.0`, suggestions can be fetched asynchronously. To enable this behavior, set the `ZSH_AUTOSUGGEST_USE_ASYNC` variable (it can be set to anything).
+Suggestions are fetched asynchronously by default in zsh versions 5.0.8 and greater. To disable asynchronous suggestions and fetch them synchronously instead, `unset ZSH_AUTOSUGGEST_USE_ASYNC` after sourcing the plugin.
+
+Alternatively, if you are using a version of zsh older than 5.0.8 and want to enable asynchronous mode, set the `ZSH_AUTOSUGGEST_USE_ASYNC` variable after sourcing the plugin (it can be set to anything). Note that there is [a bug](https://github.com/zsh-users/zsh-autosuggestions/issues/364#issuecomment-481423232) in versions of zsh older than 5.0.8 where <kbd>ctrl</kbd> + <kbd>c</kbd> will fail to reset the prompt immediately after fetching a suggestion asynchronously.
 
 ### Disabling automatic widget re-binding
 
@@ -89,13 +91,13 @@ Set `ZSH_AUTOSUGGEST_MANUAL_REBIND` (it can be set to anything) to disable autom
 
 ### Ignoring history suggestions that match a pattern
 
-Set `ZSH_AUTOSUGGEST_HISTORY_IGNORE` to a glob pattern to prevent offering suggestions for history entries that match the pattern. For example, set it to `"cd *"` to never suggest any `cd` commands from history. Or set to `"?(#c50,)"` to never suggest anything 50 characters or longer.
+Set `ZSH_AUTOSUGGEST_HISTORY_IGNORE` to a [glob pattern](http://zsh.sourceforge.net/Doc/Release/Expansion.html#Glob-Operators) to prevent offering suggestions for history entries that match the pattern. For example, set it to `"cd *"` to never suggest any `cd` commands from history. Or set to `"?(#c50,)"` to never suggest anything 50 characters or longer.
 
 **Note:** This only affects the `history` and `match_prev_cmd` suggestion strategies.
 
 ### Skipping completion suggestions for certain cases
 
-Set `ZSH_AUTOSUGGEST_COMPLETION_IGNORE` to a glob pattern to prevent offering completion suggestions when the buffer matches that pattern. For example, set it to `"git *"` to disable completion suggestions for git subcommands.
+Set `ZSH_AUTOSUGGEST_COMPLETION_IGNORE` to a [glob pattern](http://zsh.sourceforge.net/Doc/Release/Expansion.html#Glob-Operators) to prevent offering completion suggestions when the buffer matches that pattern. For example, set it to `"git *"` to disable completion suggestions for git subcommands.
 
 **Note:** This only affects the `completion` suggestion strategy.
 
@@ -168,18 +170,16 @@ Tests are written in ruby using the [`rspec`](http://rspec.info/) framework. The
 
 Test files live in `spec/`. To run the tests, run `make test`. To run a specific test, run `TESTS=spec/some_spec.rb make test`. You can also specify a `zsh` binary to use by setting the `TEST_ZSH_BIN` environment variable (ex: `TEST_ZSH_BIN=/bin/zsh make test`).
 
-A docker image for testing is available [on docker hub](https://hub.docker.com/r/ericfreese/zsh-autosuggestions-test). It comes with ruby, the bundler dependencies, and all supported versions of zsh installed.
-
-Pull the docker image with:
+It's possible to run the tests for any supported version of zsh in a Docker image by building an image from the provided Dockerfile. To build the docker image for a specific version of zsh (where `<version>` below is substituted with the contents of a line from the [`ZSH_VERSIONS`](ZSH_VERSIONS) file), run:
 
 ```sh
-docker pull ericfreese/zsh-autosuggestions-test
+docker build --build-arg TEST_ZSH_VERSION=<version> -t zsh-autosuggestions-test .
 ```
 
-To run the tests for a specific version of zsh (where `<version>` below is substituted with the contents of a line from the [`ZSH_VERSIONS`](ZSH_VERSIONS) file):
+After building the image, run the tests via:
 
 ```sh
-docker run -it -e TEST_ZSH_BIN=zsh-<version> -v $PWD:/zsh-autosuggestions zsh-autosuggestions-test make test
+docker run -it -v $PWD:/zsh-autosuggestions zsh-autosuggestions-test make test
 ```
 
 

VERSION

@@ -1 +1 @@
-v0.6.4
+v0.7.0

ZSH_VERSIONS

@@ -1,9 +1,5 @@
 # Zsh releases to run tests against
 # See https://github.com/zsh-users/zsh/releases
-#
-# When modifying this file, rebuild and push docker image:
-#   $ docker build -t ericfreese/zsh-autosuggestions-test .
-#   $ docker push ericfreese/zsh-autosuggestions-test
 4.3.11
 5.0.2
 5.0.8
@@ -14,3 +10,5 @@
 5.5.1
 5.6.2
 5.7.1
+5.8.1
+5.9

install_test_zsh.sh

@@ -2,19 +2,17 @@
 
 set -ex
 
-for v in $(grep "^[^#]" ZSH_VERSIONS); do
-  mkdir zsh-$v
-  cd zsh-$v
+mkdir zsh-build
+cd zsh-build
 
-  curl -L https://api.github.com/repos/zsh-users/zsh/tarball/zsh-$v | tar xz --strip=1
+curl -L https://api.github.com/repos/zsh-users/zsh/tarball/zsh-$TEST_ZSH_VERSION | tar xz --strip=1
 
 ./Util/preconfig
 ./configure --enable-pcre \
             --enable-cap \
             --enable-multibyte \
             --with-term-lib='ncursesw tinfo' \
-              --with-tcsetpgrp \
-              --program-suffix="-$v"
+            --with-tcsetpgrp
 
 make install.bin
 make install.modules
@@ -22,5 +20,4 @@ for v in $(grep "^[^#]" ZSH_VERSIONS); do
 
 cd ..
 
-  rm -rf zsh-$v
-done
+rm -rf zsh-build

spec/multi_line_spec.rb

@@ -1,11 +1,6 @@
 describe 'a multi-line suggestion' do
   it 'should be displayed on multiple lines' do
-    with_history(-> {
-      session.send_string('echo "')
-      session.send_keys('enter')
-      session.send_string('"')
-      session.send_keys('enter')
-    }) do
+    with_history("echo \"\n\"") do
       session.send_keys('e')
       wait_for { session.content }.to eq("echo \"\n\"")
     end

spec/options/use_async_spec.rb

@@ -1,7 +0,0 @@
-describe 'suggestion fetching' do
-  it 'is performed synchronously'
-
-  context 'when ZSH_AUTOSUGGEST_USE_ASYNC is set' do
-    it 'is performed asynchronously'
-  end
-end

spec/spec_helper.rb

@@ -1,6 +1,7 @@
 require 'pry'
 require 'rspec/wait'
 require 'terminal_session'
+require 'tempfile'
 
 RSpec.shared_context 'terminal session' do
   let(:term_opts) { {} }
@@ -21,11 +22,12 @@ RSpec.shared_context 'terminal session' do
   end
 
   def with_history(*commands, &block)
-    session.run_command('fc -p')
+    Tempfile.create do |f|
+      f.write(commands.map{|c| c.gsub("\n", "\\\n")}.join("\n"))
+      f.flush
 
-    commands.each do |c|
-      c.respond_to?(:call) ? c.call : session.run_command(c)
-    end
+      session.run_command('fc -p')
+      session.run_command("fc -R #{f.path}")
 
       session.clear_screen
 
@@ -35,6 +37,7 @@ RSpec.shared_context 'terminal session' do
       session.run_command('fc -P')
     end
   end
+end
 
 RSpec.configure do |config|
   config.expect_with :rspec do |expectations|

spec/strategies/special_characters_helper.rb

@@ -1,58 +1,71 @@
 shared_examples 'special characters' do
-  describe 'a special character in the buffer' do
-    it 'should be treated like any other character' do
+  describe 'a special character in the buffer should be treated like any other character' do
+    it 'asterisk' do
       with_history('echo "hello*"', 'echo "hello."') do
         session.send_string('echo "hello*')
         wait_for { session.content }.to eq('echo "hello*"')
       end
+    end
 
+    it 'question mark' do
       with_history('echo "hello?"', 'echo "hello."') do
         session.send_string('echo "hello?')
         wait_for { session.content }.to eq('echo "hello?"')
       end
+    end
 
+    it 'backslash' do
       with_history('echo "hello\nworld"') do
         session.send_string('echo "hello\\')
         wait_for { session.content }.to eq('echo "hello\nworld"')
       end
+    end
 
+    it 'double backslash' do
       with_history('echo "\\\\"') do
         session.send_string('echo "\\\\')
         wait_for { session.content }.to eq('echo "\\\\"')
       end
+    end
 
+    it 'tilde' do
       with_history('echo ~/foo') do
         session.send_string('echo ~')
         wait_for { session.content }.to eq('echo ~/foo')
       end
+    end
 
+    it 'parentheses' do
       with_history('echo "$(ls foo)"') do
         session.send_string('echo "$(')
         wait_for { session.content }.to eq('echo "$(ls foo)"')
       end
+    end
 
+    it 'square bracket' do
       with_history('echo "$history[123]"') do
         session.send_string('echo "$history[')
         wait_for { session.content }.to eq('echo "$history[123]"')
         session.send_string('123]')
         wait_for { session.content }.to eq('echo "$history[123]"')
       end
+    end
 
+    it 'octothorpe' do
       with_history('echo "#yolo"') do
         session.send_string('echo "#')
         wait_for { session.content }.to eq('echo "#yolo"')
       end
-
-      with_history('echo "#foo"', 'echo $#abc') do
-        session.send_string('echo "#')
-        wait_for { session.content }.to eq('echo "#foo"')
     end
 
+    it 'caret' do
       with_history('echo "^A"', 'echo "^B"') do
         session.send_string('echo "^A')
         wait_for { session.content }.to eq('echo "^A"')
       end
+    end
 
+    it 'dash' do
       with_history('-foo() {}') do
         session.send_string('-')
         wait_for { session.content }.to eq('-foo() {}')

src/async.zsh

@@ -44,7 +44,7 @@ _zsh_autosuggest_async_request() {
 
 	# There's a weird bug here where ^C stops working unless we force a fork
 	# See https://github.com/zsh-users/zsh-autosuggestions/issues/364
-	command true
+	is-at-least 5.8 || command true
 
 	# Read the pid from the child process
 	read _ZSH_AUTOSUGGEST_CHILD_PID <&$_ZSH_AUTOSUGGEST_ASYNC_FD
@@ -64,7 +64,7 @@ _zsh_autosuggest_async_response() {
 	if [[ -z "$2" || "$2" == "hup" ]]; then
 		# Read everything from the fd and give it as a suggestion
 		IFS='' read -rd '' -u $1 suggestion
-		zle autosuggest-suggest -- "$suggestion"
+		_zsh_autosuggest_async_suggest "$suggestion"
 
 		# Close the fd
 		exec {1}<&-
@@ -73,3 +73,14 @@ _zsh_autosuggest_async_response() {
 	# Always remove the handler
 	zle -F "$1"
 }
+
+_zsh_autosuggest_async_suggest() {
+	# Before 5.9, async suggestions break widgets that rely on LASTWIDGET
+	# such as copy-earlier-word and {up,down}-line-or-beginning-search. In
+	# 5.9, a flag was added to `zle` that will skip setting LASTWIDGET so
+	# that those widgets that depend on it will continue to work
+	# See https://www.zsh.org/mla/workers/2020/msg00824.html
+	local nolast
+	is-at-least 5.9 && nolast=supported
+	zle autosuggest-suggest ${=nolast:+-f nolast} -- "$1"
+}

src/bind.zsh

@@ -69,7 +69,7 @@ _zsh_autosuggest_bind_widgets() {
 	ignore_widgets=(
 		.\*
 		_\*
-		autosuggest-\*
+		${_ZSH_AUTOSUGGEST_BUILTIN_ACTIONS/#/autosuggest-}
 		$ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX\*
 		$ZSH_AUTOSUGGEST_IGNORE_WIDGETS
 	)

src/start.zsh

@@ -18,6 +18,16 @@ _zsh_autosuggest_start() {
 	_zsh_autosuggest_bind_widgets
 }
 
+# Mark for auto-loading the functions that we use
+autoload -Uz add-zsh-hook is-at-least
+
+# Automatically enable asynchronous mode in newer versions of zsh. Disable for
+# older versions because there is a bug when using async mode where ^C does not
+# work immediately after fetching a suggestion.
+# See https://github.com/zsh-users/zsh-autosuggestions/issues/364
+if is-at-least 5.0.8; then
+	typeset -g ZSH_AUTOSUGGEST_USE_ASYNC=
+fi
+
 # Start the autosuggestion widgets on the next precmd
-autoload -Uz add-zsh-hook
 add-zsh-hook precmd _zsh_autosuggest_start

src/strategies/completion.zsh

@@ -45,8 +45,6 @@ _zsh_autosuggest_capture_completion_widget() {
 zle -N autosuggest-capture-completion _zsh_autosuggest_capture_completion_widget
 
 _zsh_autosuggest_capture_setup() {
-	autoload -Uz is-at-least
-
 	# 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

src/widgets.zsh

@@ -20,7 +20,7 @@ _zsh_autosuggest_enable() {
 
 # Toggle suggestions (enable/disable)
 _zsh_autosuggest_toggle() {
-	if [[ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]]; then
+	if (( ${+_ZSH_AUTOSUGGEST_DISABLED} )); then
 		_zsh_autosuggest_enable
 	else
 		_zsh_autosuggest_disable
@@ -61,25 +61,14 @@ _zsh_autosuggest_modify() {
 		return $retval
 	fi
 
-	# Optimize if manually typing in the suggestion
-	if (( $#BUFFER > $#orig_buffer )); then
-		local added=${BUFFER#$orig_buffer}
-
-		# If the string added matches the beginning of the postdisplay
-		if [[ "$added" = "${orig_postdisplay:0:$#added}" ]]; then
-			POSTDISPLAY="${orig_postdisplay:$#added}"
-			return $retval
-		fi
-	fi
-
-	# Don't fetch a new suggestion if the buffer hasn't changed
-	if [[ "$BUFFER" = "$orig_buffer" ]]; then
-		POSTDISPLAY="$orig_postdisplay"
+	# Optimize if manually typing in the suggestion or if buffer hasn't changed
+	if [[ "$BUFFER" = "$orig_buffer"* && "$orig_postdisplay" = "${BUFFER:$#orig_buffer}"* ]]; then
+		POSTDISPLAY="${orig_postdisplay:$(($#BUFFER - $#orig_buffer))}"
 		return $retval
 	fi
 
 	# Bail out if suggestions are disabled
-	if [[ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]]; then
+	if (( ${+_ZSH_AUTOSUGGEST_DISABLED} )); then
 		return $?
 	fi
 
@@ -205,8 +194,21 @@ _zsh_autosuggest_partial_accept() {
 }
 
 () {
+	typeset -ga _ZSH_AUTOSUGGEST_BUILTIN_ACTIONS
+
+	_ZSH_AUTOSUGGEST_BUILTIN_ACTIONS=(
+		clear
+		fetch
+		suggest
+		accept
+		execute
+		enable
+		disable
+		toggle
+	)
+
 	local action
-	for action in clear modify fetch suggest accept partial_accept execute enable disable toggle; do
+	for action in $_ZSH_AUTOSUGGEST_BUILTIN_ACTIONS modify partial_accept; do
 		eval "_zsh_autosuggest_widget_$action() {
 			local -i retval
 
@@ -223,12 +225,7 @@ _zsh_autosuggest_partial_accept() {
 		}"
 	done
 
-	zle -N autosuggest-fetch _zsh_autosuggest_widget_fetch
-	zle -N autosuggest-suggest _zsh_autosuggest_widget_suggest
-	zle -N autosuggest-accept _zsh_autosuggest_widget_accept
-	zle -N autosuggest-clear _zsh_autosuggest_widget_clear
-	zle -N autosuggest-execute _zsh_autosuggest_widget_execute
-	zle -N autosuggest-enable _zsh_autosuggest_widget_enable
-	zle -N autosuggest-disable _zsh_autosuggest_widget_disable
-	zle -N autosuggest-toggle _zsh_autosuggest_widget_toggle
+	for action in $_ZSH_AUTOSUGGEST_BUILTIN_ACTIONS; do
+		zle -N autosuggest-$action _zsh_autosuggest_widget_$action
+	done
 }

zsh-autosuggestions.zsh

@@ -1,8 +1,8 @@
 # Fish-like fast/unobtrusive autosuggestions for zsh.
 # https://github.com/zsh-users/zsh-autosuggestions
-# v0.6.4
+# v0.7.0
 # Copyright (c) 2013 Thiago de Arruda
-# Copyright (c) 2016-2019 Eric Freese
+# Copyright (c) 2016-2021 Eric Freese
 # 
 # Permission is hereby granted, free of charge, to any person
 # obtaining a copy of this software and associated documentation
@@ -199,7 +199,7 @@ _zsh_autosuggest_bind_widgets() {
 	ignore_widgets=(
 		.\*
 		_\*
-		autosuggest-\*
+		${_ZSH_AUTOSUGGEST_BUILTIN_ACTIONS/#/autosuggest-}
 		$ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX\*
 		$ZSH_AUTOSUGGEST_IGNORE_WIDGETS
 	)
@@ -282,7 +282,7 @@ _zsh_autosuggest_enable() {
 
 # Toggle suggestions (enable/disable)
 _zsh_autosuggest_toggle() {
-	if [[ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]]; then
+	if (( ${+_ZSH_AUTOSUGGEST_DISABLED} )); then
 		_zsh_autosuggest_enable
 	else
 		_zsh_autosuggest_disable
@@ -323,25 +323,14 @@ _zsh_autosuggest_modify() {
 		return $retval
 	fi
 
-	# Optimize if manually typing in the suggestion
-	if (( $#BUFFER > $#orig_buffer )); then
-		local added=${BUFFER#$orig_buffer}
-
-		# If the string added matches the beginning of the postdisplay
-		if [[ "$added" = "${orig_postdisplay:0:$#added}" ]]; then
-			POSTDISPLAY="${orig_postdisplay:$#added}"
-			return $retval
-		fi
-	fi
-
-	# Don't fetch a new suggestion if the buffer hasn't changed
-	if [[ "$BUFFER" = "$orig_buffer" ]]; then
-		POSTDISPLAY="$orig_postdisplay"
+	# Optimize if manually typing in the suggestion or if buffer hasn't changed
+	if [[ "$BUFFER" = "$orig_buffer"* && "$orig_postdisplay" = "${BUFFER:$#orig_buffer}"* ]]; then
+		POSTDISPLAY="${orig_postdisplay:$(($#BUFFER - $#orig_buffer))}"
 		return $retval
 	fi
 
 	# Bail out if suggestions are disabled
-	if [[ -n "${_ZSH_AUTOSUGGEST_DISABLED+x}" ]]; then
+	if (( ${+_ZSH_AUTOSUGGEST_DISABLED} )); then
 		return $?
 	fi
 
@@ -467,8 +456,21 @@ _zsh_autosuggest_partial_accept() {
 }
 
 () {
+	typeset -ga _ZSH_AUTOSUGGEST_BUILTIN_ACTIONS
+
+	_ZSH_AUTOSUGGEST_BUILTIN_ACTIONS=(
+		clear
+		fetch
+		suggest
+		accept
+		execute
+		enable
+		disable
+		toggle
+	)
+
 	local action
-	for action in clear modify fetch suggest accept partial_accept execute enable disable toggle; do
+	for action in $_ZSH_AUTOSUGGEST_BUILTIN_ACTIONS modify partial_accept; do
 		eval "_zsh_autosuggest_widget_$action() {
 			local -i retval
 
@@ -485,14 +487,9 @@ _zsh_autosuggest_partial_accept() {
 		}"
 	done
 
-	zle -N autosuggest-fetch _zsh_autosuggest_widget_fetch
-	zle -N autosuggest-suggest _zsh_autosuggest_widget_suggest
-	zle -N autosuggest-accept _zsh_autosuggest_widget_accept
-	zle -N autosuggest-clear _zsh_autosuggest_widget_clear
-	zle -N autosuggest-execute _zsh_autosuggest_widget_execute
-	zle -N autosuggest-enable _zsh_autosuggest_widget_enable
-	zle -N autosuggest-disable _zsh_autosuggest_widget_disable
-	zle -N autosuggest-toggle _zsh_autosuggest_widget_toggle
+	for action in $_ZSH_AUTOSUGGEST_BUILTIN_ACTIONS; do
+		zle -N autosuggest-$action _zsh_autosuggest_widget_$action
+	done
 }
 
 #--------------------------------------------------------------------#
@@ -541,8 +538,6 @@ _zsh_autosuggest_capture_completion_widget() {
 zle -N autosuggest-capture-completion _zsh_autosuggest_capture_completion_widget
 
 _zsh_autosuggest_capture_setup() {
-	autoload -Uz is-at-least
-
 	# 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
@@ -804,7 +799,7 @@ _zsh_autosuggest_async_request() {
 
 	# There's a weird bug here where ^C stops working unless we force a fork
 	# See https://github.com/zsh-users/zsh-autosuggestions/issues/364
-	command true
+	is-at-least 5.8 || command true
 
 	# Read the pid from the child process
 	read _ZSH_AUTOSUGGEST_CHILD_PID <&$_ZSH_AUTOSUGGEST_ASYNC_FD
@@ -824,7 +819,7 @@ _zsh_autosuggest_async_response() {
 	if [[ -z "$2" || "$2" == "hup" ]]; then
 		# Read everything from the fd and give it as a suggestion
 		IFS='' read -rd '' -u $1 suggestion
-		zle autosuggest-suggest -- "$suggestion"
+		_zsh_autosuggest_async_suggest "$suggestion"
 
 		# Close the fd
 		exec {1}<&-
@@ -834,6 +829,17 @@ _zsh_autosuggest_async_response() {
 	zle -F "$1"
 }
 
+_zsh_autosuggest_async_suggest() {
+	# Before 5.9, async suggestions break widgets that rely on LASTWIDGET
+	# such as copy-earlier-word and {up,down}-line-or-beginning-search. In
+	# 5.9, a flag was added to `zle` that will skip setting LASTWIDGET so
+	# that those widgets that depend on it will continue to work
+	# See https://www.zsh.org/mla/workers/2020/msg00824.html
+	local nolast
+	is-at-least 5.9 && nolast=supported
+	zle autosuggest-suggest ${=nolast:+-f nolast} -- "$1"
+}
+
 #--------------------------------------------------------------------#
 # Start                                                              #
 #--------------------------------------------------------------------#
@@ -853,6 +859,16 @@ _zsh_autosuggest_start() {
 	_zsh_autosuggest_bind_widgets
 }
 
+# Mark for auto-loading the functions that we use
+autoload -Uz add-zsh-hook is-at-least
+
+# Automatically enable asynchronous mode in newer versions of zsh. Disable for
+# older versions because there is a bug when using async mode where ^C does not
+# work immediately after fetching a suggestion.
+# See https://github.com/zsh-users/zsh-autosuggestions/issues/364
+if is-at-least 5.0.8; then
+	typeset -g ZSH_AUTOSUGGEST_USE_ASYNC=
+fi
+
 # Start the autosuggestion widgets on the next precmd
-autoload -Uz add-zsh-hook
 add-zsh-hook precmd _zsh_autosuggest_start