Add opt-in Node.js version display

package.json

@@ -20,6 +20,7 @@
 		"postinstall": "if [ -e /opt/homebrew/bin/zsh ]; then PURE_DEST=/opt/homebrew/share/zsh/site-functions npm run --silent postinstall-link && exit 0; elif [ -e /usr/local/bin/zsh ]; then PURE_DEST=/usr/local/share/zsh/site-functions npm run --silent postinstall-link && exit 0; elif [ -e /bin/zsh ] || [ -e /usr/bin/zsh ]; then for dest in /usr/share/zsh/site-functions /usr/local/share/zsh/site-functions; do if [ -d $dest ]; then PURE_DEST=$dest npm run --silent postinstall-link && exit 0; fi; done; fi; PURE_DEST=\"$PWD/functions\" npm run --silent postinstall-link && npm run --silent postinstall-fail-instructions",
 		"postinstall-link": "mkdir -p \"$PURE_DEST\" && ln -sf \"$PWD/pure.zsh\" \"$PURE_DEST/prompt_pure_setup\" && ln -sf \"$PWD/async.zsh\" \"$PURE_DEST/async\"",
 		"postinstall-fail-instructions": "echo \"\\nERROR: Could not automagically symlink the prompt. You can either:\\n\\n1. Add the following to your \\`.zshrc\\`:\\n\\n    fpath+=('$PWD/functions')\\n\\n2. Or check out the readme on how to do it manually: https://github.com/sindresorhus/pure#manually\"",
+		"test": "zsh tests/test.zsh",
 		"version": "sed -i '' -e 's/prompt_pure_state\\[version\\]=.*/prompt_pure_state[version]=\"'\"$npm_package_version\"'\"/' pure.zsh && git add pure.zsh"
 	},
 	"files": [

pure.zsh

@@ -155,6 +155,14 @@ prompt_pure_preprompt_render() {
 	# psvar[19]: Command execution time.
 	psvar[19]=${prompt_pure_cmd_exec_time}
 
+	# psvar[21]: Node.js version.
+	psvar[21]=
+	if [[ -n $prompt_pure_node_version ]]; then
+		local node_symbol
+		zstyle -s ":prompt:pure:environment:node_version" symbol node_symbol || node_symbol='⬢'
+		psvar[21]="${node_symbol}${prompt_pure_node_version}"
+	fi
+
 	# Expand the prompt for future comparison.
 	local expanded_prompt
 	expanded_prompt="${(S%%)PROMPT}"
@@ -368,6 +376,25 @@ prompt_pure_async_git_stash() {
 	git rev-list --walk-reflogs --count refs/stash
 }
 
+prompt_pure_check_node_version() {
+	setopt localoptions noshwordsplit
+
+	# Walk up to find package.json (similar to how git detects repos).
+	local dir=$PWD
+	while [[ $dir != "/" ]]; do
+		[[ -f "$dir/package.json" ]] && break
+		dir=${dir:h}
+	done
+
+	local version=
+	if [[ -f "$dir/package.json" ]]; then
+		version=$(command node --version 2>/dev/null) || version=
+		version=${${${version#v}%%.*}//[$'\t\r\n']}
+	fi
+
+	print -r -- "$version"
+}
+
 # Try to lower the priority of the worker so that disk heavy operations
 # like `git status` has less impact on the system responsivity.
 prompt_pure_async_renice() {
@@ -409,19 +436,35 @@ prompt_pure_async_tasks() {
 		# Stop any running async jobs.
 		async_flush_jobs "prompt_pure"
 
-		# Reset Git preprompt variables, switching working tree.
+		# Reset preprompt variables, switching working tree.
 		unset prompt_pure_git_dirty
 		unset prompt_pure_git_last_dirty_check_timestamp
 		unset prompt_pure_git_arrows
 		unset prompt_pure_git_stash
 		unset prompt_pure_git_fetch_pattern
+		unset prompt_pure_node_version
+		unset prompt_pure_node_version_path
+		unset prompt_pure_node_version_pwd
 		prompt_pure_vcs_info[branch]=
 		prompt_pure_vcs_info[top]=
 	fi
 	unset MATCH MBEGIN MEND
 
 	async_job "prompt_pure" prompt_pure_async_vcs_info
 
+	# Check if Node.js version display is enabled (independent of Git).
+	if zstyle -t ":prompt:pure:environment:node_version" show; then
+		if [[ ${prompt_pure_node_version_pwd-} != $PWD ]] || [[ ${prompt_pure_node_version_path-} != $PATH ]]; then
+			typeset -g prompt_pure_node_version=$(prompt_pure_check_node_version)
+			typeset -g prompt_pure_node_version_pwd=$PWD
+			typeset -g prompt_pure_node_version_path=$PATH
+		fi
+	else
+		unset prompt_pure_node_version
+		unset prompt_pure_node_version_path
+		unset prompt_pure_node_version_pwd
+	fi
+
 	# Only perform tasks inside a Git working tree.
 	[[ -n $prompt_pure_vcs_info[top] ]] || return
 
@@ -812,6 +855,7 @@ prompt_pure_setup() {
 		git:action           yellow
 		git:dirty            218
 		host                 242
+		node_version         green
 		path                 blue
 		prompt:error         red
 		prompt:success       magenta
@@ -841,7 +885,7 @@ prompt_pure_setup() {
 	typeset -g prompt_pure_git_branch_color=$prompt_pure_colors[git:branch]
 
 	# Construct PROMPT once, both preprompt and prompt line. Kept
-	# dynamic via variables and psvar[12-20], updated each render
+	# dynamic via variables and psvar[12-21], updated each render
 	# in prompt_pure_preprompt_render. Numbering starts at 12 for
 	# legacy reasons (Pure originally used psvar[12] for virtualenv)
 	# and to avoid collisions with low psvar indices which users
@@ -856,10 +900,11 @@ prompt_pure_setup() {
 	#   psvar[18] = git stash flag, renders stash symbol
 	#   psvar[19] = exec time (e.g. 1d 3h 2m 5s)
 	#   psvar[20] = virtualenv/conda/nix-shell name
+	#   psvar[21] = Node.js version (e.g. ⬢22)
 	#
 	# Example output:
 	#   ✦ user@host ~/Code/pure main* rebase ⇣⇡ ≡ 3s
-	#   myenv ❯
+	#   myenv ⬢22 ❯
 	#
 	# Preprompt line: each %(NV..) section only renders when its psvar is non-empty.
 	PROMPT='%(12V.%F{$prompt_pure_colors[suspended_jobs]}%12v%f .)'
@@ -874,8 +919,9 @@ prompt_pure_setup() {
 	# Newline separating preprompt from prompt.
 	PROMPT+='${prompt_newline}'
 
-	# Prompt line: virtualenv and prompt symbol.
+	# Prompt line: virtualenv, Node.js version, and prompt symbol.
 	PROMPT+='%(20V.%F{$prompt_pure_colors[virtualenv]}%20v%f .)'
+	PROMPT+='%(21V.%F{$prompt_pure_colors[node_version]}%21v%f .)'
 	# Prompt symbol: turns red if the previous command didn't exit with 0.
 	local prompt_indicator='%(?.%F{$prompt_pure_colors[prompt:success]}.%F{$prompt_pure_colors[prompt:error]})${prompt_pure_state[prompt]}%f '
 	PROMPT+=$prompt_indicator

readme.md

@@ -95,6 +95,14 @@ You can set Pure to only `git fetch` the upstream branch of the current local br
 
 `zstyle :prompt:pure:git:fetch only_upstream yes`
 
+Node.js version display shows the current major `node` version when inside a directory tree containing a `package.json`. It is not enabled by default. You can enable it with:
+
+`zstyle :prompt:pure:environment:node_version show yes`
+
+You can change the symbol shown before the Node.js version (default `⬢`) with:
+
+`zstyle :prompt:pure:environment:node_version symbol ⬡`
+
 `nix-shell` integration adds the shell name to the prompt when used from within a nix shell. It is enabled by default, you can disable it with:
 
 `zstyle :prompt:pure:environment:nix-shell show no`
@@ -115,6 +123,7 @@ Colors can be changed by using [`zstyle`](http://zsh.sourceforge.net/Doc/Release
 - `git:action` (yellow) - The current action in progress (cherry-pick, rebase, etc.) when in a Git repository.
 - `git:dirty` (218) - The asterisk showing the branch is dirty.
 - `host` (242) - The hostname when on a remote machine.
+- `node_version` (green) - The current major Node.js version in directories with `package.json`.
 - `path` (blue) - The current path, for example, `PWD`.
 - `prompt:error` (red) - The `PURE_PROMPT_SYMBOL` when the previous command has *failed*.
 - `prompt:success` (magenta) - The `PURE_PROMPT_SYMBOL` when the previous command has *succeeded*.
@@ -138,10 +147,11 @@ The following diagram shows where each color is applied on the prompt:
 │      │           │          │     │ │        │ │ ┌─── execution_time
 │      │           │          │     │ │        │ │ │
 zaphod@heartofgold ~/dev/pure master* rebase-i ⇡ ≡ 42s
-venv ❯
-│    │
-│    └───────────────────────────────────────────────── prompt
-└────────────────────────────────────────────────────── virtualenv (or prompt:continuation)
+venv ⬢22 ❯
+│    │       │
+│    │       └──────────────────────────────────────── prompt
+│    └──────────────────────────────────────────────── node_version
+└───────────────────────────────────────────────────── virtualenv (or prompt:continuation)
 ```
 
 ### RGB colors

tests/node-version.zsh

@@ -0,0 +1,85 @@
+#!/usr/bin/env zsh
+
+source "${0:A:h}/test-helper.zsh"
+
+main() {
+	local base_directory=/tmp/pure-node-version-$$
+	local bin_directory=$base_directory/bin
+	local second_bin_directory=$base_directory/bin-second
+	local project_directory=$base_directory/project
+	local nested_directory=$project_directory/deep/nested
+	local outside_directory=$base_directory/outside
+	local counter_path=$base_directory/node-count
+
+	mkdir -p -- "$bin_directory" "$second_bin_directory" "$nested_directory" "$outside_directory"
+	: > "$project_directory/package.json"
+	: > "$counter_path"
+
+	local node_path=$bin_directory/node
+	cat > "$node_path" <<EOF
+#!/bin/sh
+count=\$(cat "$counter_path")
+count=\$((count + 1))
+printf '%s' "\$count" > "$counter_path"
+printf '%s\n' 'v25.8.0'
+EOF
+	chmod +x "$node_path"
+
+	local second_node_path=$second_bin_directory/node
+	cat > "$second_node_path" <<EOF
+#!/bin/sh
+count=\$(cat "$counter_path")
+count=\$((count + 1))
+printf '%s' "\$count" > "$counter_path"
+printf '%s\n' 'v26.1.0'
+EOF
+	chmod +x "$second_node_path"
+
+	prompt_pure_async_init() {
+		:
+	}
+
+	async_worker_eval() {
+		:
+	}
+
+	async_flush_jobs() {
+		:
+	}
+
+	async_job() {
+		:
+	}
+
+	typeset -gA prompt_pure_vcs_info=(pwd '' top '')
+	zstyle ':prompt:pure:environment:node_version' show yes
+
+	PATH="$bin_directory:/usr/bin:/bin"
+	builtin cd -q "$nested_directory"
+	prompt_pure_async_tasks || :
+	assert_equal "25" "${prompt_pure_node_version-}" "node version should be set synchronously inside a package.json tree"
+	assert_equal "1" "$(cat "$counter_path")" "node should be resolved on the first prompt in a package.json tree"
+
+	prompt_pure_async_tasks || :
+	assert_equal "25" "${prompt_pure_node_version-}" "node version should be reused when directory and PATH do not change"
+	assert_equal "1" "$(cat "$counter_path")" "node should not be resolved again when directory and PATH are unchanged"
+
+	PATH="$second_bin_directory:/usr/bin:/bin"
+	prompt_pure_async_tasks || :
+	assert_equal "26" "${prompt_pure_node_version-}" "node version should be refreshed when PATH changes"
+	assert_equal "2" "$(cat "$counter_path")" "node should be resolved again when PATH changes"
+
+	builtin cd -q "$outside_directory"
+	prompt_pure_async_tasks || :
+	assert_empty "${prompt_pure_node_version-}" "node version should be cleared outside a package.json tree"
+
+	zstyle ':prompt:pure:environment:node_version' show no
+	builtin cd -q "$nested_directory"
+	typeset -g prompt_pure_node_version=stale
+	prompt_pure_async_tasks || :
+	assert_empty "${prompt_pure_node_version-}" "node version should stay disabled when the style is off"
+
+	print -- "node-version tests passed"
+}
+
+main "$@"

tests/test-helper.zsh

@@ -0,0 +1,40 @@
+#!/usr/bin/env zsh
+
+set -euo pipefail
+
+cd -- "${0:A:h}/.."
+
+source ./pure.zsh >/dev/null 2>&1
+
+prompt_pure_preprompt_render() {
+	:
+}
+
+node_output() {
+	print -r -- "${1}"$'\t'"${2-}"
+}
+
+assert_equal() {
+	local expected=$1
+	local actual=$2
+	local message=$3
+
+	if [[ $expected != $actual ]]; then
+		print -u2 -- "Assertion failed: $message"
+		print -u2 -- "Expected: $expected"
+		print -u2 -- "Actual:   $actual"
+		return 1
+	fi
+}
+
+assert_empty() {
+	local actual=$1
+	local message=$2
+
+	if [[ -n $actual ]]; then
+		print -u2 -- "Assertion failed: $message"
+		print -u2 -- "Expected empty value"
+		print -u2 -- "Actual: $actual"
+		return 1
+	fi
+}

tests/test.zsh

@@ -0,0 +1,15 @@
+#!/usr/bin/env zsh
+
+set -euo pipefail
+
+cd -- "${0:A:h}"
+
+local test_file
+for test_file in *.zsh; do
+	if [[ $test_file == test.zsh || $test_file == test-helper.zsh ]]; then
+		continue
+	fi
+
+	print -- "Running $test_file"
+	zsh "$test_file"
+done