Add package-json subcommand

bin/JSON.sh

@@ -0,0 +1 @@
+../node_modules/JSON.sh/JSON.sh

bin/nodenv-package-json

@@ -0,0 +1 @@
+../libexec/nodenv-package-json

bin/semver.sh

@@ -0,0 +1 @@
+../node_modules/sh-semver/semver.sh

etc/nodenv.d/version-name/package-json-engine.bash

@@ -1,11 +1,10 @@
-#!/bin/bash
-
-# shellcheck source=libexec/nodenv-package-json-engine
-source "$(plugin_root)/libexec/nodenv-package-json-engine"
+if [ -n "$(nodenv-sh-shell 2>/dev/null)" ] ||
+  [ -n "$(nodenv-local 2>/dev/null)" ]; then
+  return
+fi
 
-if ! NODENV_PACKAGE_JSON_VERSION=$(get_version_respecting_precedence); then
-  echo "package-json-engine: version satisfying \`$(get_expression_respecting_precedence)' not installed" >&2
-  exit 1
-elif [ -n "$NODENV_PACKAGE_JSON_VERSION" ]; then
-  export NODENV_VERSION="${NODENV_PACKAGE_JSON_VERSION}"
+if NODENV_PACKAGE_JSON_VERSION=$(nodenv-package-json 2>/dev/null) &&
+  [ -n "$NODENV_PACKAGE_JSON_VERSION" ]; then
+  # shellcheck disable=2034
+  NODENV_VERSION=$NODENV_PACKAGE_JSON_VERSION
 fi

etc/nodenv.d/version-origin/package-json-engine.bash

@@ -1,9 +1,33 @@
-#!/bin/bash
+if [ -n "$(nodenv-sh-shell 2>/dev/null)" ] ||
+  [ -n "$(nodenv-local 2>/dev/null)" ]; then
+  return
+fi
+
+READLINK=$(type -p greadlink readlink | head -1)
+[ -n "$READLINK" ] || return 1
+
+abs_dirname() {
+  local cwd="$PWD"
+  local path="$1"
+
+  while [ -n "$path" ]; do
+    cd "${path%/*}" || return 1
+    local name="${path##*/}"
+    path="$($READLINK "$name" || true)"
+  done
+
+  pwd
+  cd "$cwd" || return 1
+}
+
+bin_path="$(abs_dirname "${BASH_SOURCE[0]}")/../../../libexec"
 
-# shellcheck source=libexec/nodenv-package-json-engine
-source "$(plugin_root)/libexec/nodenv-package-json-engine"
+[ -d "$bin_path" ] || return 1
 
-ENGINES_EXPRESSION=$(get_expression_respecting_precedence);
-if [ -n "$ENGINES_EXPRESSION" ]; then
-  export NODENV_VERSION_ORIGIN="package-json-engine matching $ENGINES_EXPRESSION"
+if NODENV_PACKAGE_JSON_VERSION=$(nodenv-package-json 2>/dev/null) &&
+  [ -n "$NODENV_PACKAGE_JSON_VERSION" ]; then
+  NODENV_PACKAGE_JSON_FILE=$("$bin_path/nodenv-package-json-file")
+  NODENV_PACKAGE_JSON_SPEC=$("$bin_path/nodenv-package-json-file-read" "$NODENV_PACKAGE_JSON_FILE")
+  # shellcheck disable=2034
+  NODENV_VERSION_ORIGIN="satisfying \`$NODENV_PACKAGE_JSON_SPEC' from $NODENV_PACKAGE_JSON_FILE#engines.node"
 fi

libexec/nodenv-package-json

@@ -0,0 +1,77 @@
+#!/usr/bin/env bash
+#
+# Usage: nodenv package-json
+# Summary: Show the local application-specific Node version from package.json
+#
+# Shows the highest-installed node version satisfying package.json#engines.
+#
+
+set -e
+[ -n "$NODENV_DEBUG" ] && set -x
+
+abort() {
+  echo "package-json-engine: $1" >&2
+  exit 1
+}
+
+READLINK=$(type -p greadlink readlink | head -1)
+[ -n "$READLINK" ] || abort "cannot find readlink - are you missing GNU coreutils?"
+
+abs_dirname() {
+  local cwd="$PWD"
+  local path="$1"
+
+  while [ -n "$path" ]; do
+    cd "${path%/*}"
+    local name="${path##*/}"
+    path="$($READLINK "$name" || true)"
+  done
+
+  pwd
+  cd "$cwd"
+}
+
+bin_path="$(abs_dirname "$0")"
+
+matching_version() {
+  local version_spec=$1
+  local -a installed_versions
+  while IFS= read -r v; do
+    installed_versions+=( "$v" )
+  done < <(nodenv versions --bare --skip-aliases | grep -e '^[[:digit:]]')
+
+  local fast_guess
+  fast_guess=$(semver.sh -r "$version_spec" "${installed_versions[@]:${#installed_versions[@]}-1}" | tail -n 1)
+
+  # Most #engine version specs just specify a baseline version,
+  # which means most likely, the highest installed version will satisfy
+  # This does a first pass with just that single version in hopes it satisfies.
+  # If so, we can avoid the cost of sh-semver sorting and validating across
+  # all the installed versions.
+  if [ -n "$fast_guess" ]; then
+    echo "$fast_guess"
+    return 0
+  fi
+
+  local match
+  match=$(semver.sh -r "$version_spec" "${installed_versions[@]}" | tail -n 1)
+
+  if [ -n "$match" ]; then
+    echo "$match"
+  else
+    return 1
+  fi
+}
+
+
+if ! NODENV_PACKAGE_JSON_FILE="$("$bin_path/nodenv-package-json-file")"; then
+  abort "no package.json found for this directory"
+fi
+
+if ! version_spec="$("$bin_path/nodenv-package-json-file-read" "$NODENV_PACKAGE_JSON_FILE")"; then
+  abort "no engine version configured for this package"
+fi
+
+if ! matching_version "$version_spec"; then
+  abort "no version found satisfying \`$version_spec'"
+fi

libexec/nodenv-package-json-file

@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+#
+# Usage: package-file [<dir>]
+# Summary: Detect the package.json that sets the current nodenv version
+# Options:
+#   <dir>    Directory from which to find package.json
+#            [default: ${NODENV_DIR:-PWD}]
+
+set -e
+[ -n "$NODENV_DEBUG" ] && set -x
+
+target_dir="$1"
+
+find_package_json() {
+  local package_json root="$1"
+  while ! [[ "$root" =~ ^//[^/]*$ ]]; do
+    package_json="$root/package.json"
+
+    if [ -f "$package_json" ] &&
+      [ -r "$package_json" ] &&
+      [ -s "$package_json" ]; then
+      echo "$package_json"
+      return 0
+    fi
+    [ -n "$root" ] || break
+    root="${root%/*}"
+  done
+  return 1
+}
+
+if [ -n "$target_dir" ]; then
+  find_package_json "$target_dir"
+else
+  find_package_json "$NODENV_DIR" || {
+    [ "$NODENV_DIR" != "$PWD" ] && find_package_json "$PWD"
+  }
+fi

libexec/nodenv-package-json-file-read

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+# Usage: nodenv package-json-file-read <file>
+#
+# Summary: Show the engines version-spec from package.json
+# Options:
+#   <file>    Package.json file to read from
+#
+
+set -e
+[ -n "$NODENV_DEBUG" ] && set -x
+
+PACKAGE_JSON_FILE=$1
+
+[ -f "$PACKAGE_JSON_FILE" ] || exit 1
+
+extract_expression() {
+  local version_regex='\["engines","node"\][[:space:]]*"([^"]*)"'
+  # -b -n gives minimal output - see https://github.com/dominictarr/JSON.sh#options
+  if [[ $(JSON.sh -b -n 2>/dev/null) =~ $version_regex ]]; then
+    echo "${BASH_REMATCH[1]}"
+  else
+    return 1
+  fi
+}
+
+extract_expression < "$PACKAGE_JSON_FILE"

package.json

@@ -15,6 +15,7 @@
   "bugs": {
     "url": "https://github.com/nodenv/nodenv-package-json-engine/issues"
   },
+  "bin": "libexec/nodenv-package-json",
   "directories": {
     "bin": "bin",
     "test": "test"
@@ -25,7 +26,7 @@
     "libexec"
   ],
   "scripts": {
-    "lint": "git ls-files bin etc libexec test/*.bash | xargs shellcheck",
+    "lint": "git ls-files etc libexec test/*.bash | xargs shellcheck",
     "test": "bats ${CI:+--tap} test",
     "posttest": "npm run lint",
     "postversion": "npm publish",