Closes #11

Retrieve package version information via `Node` script rather than
`bash` to address #11

package.json

@@ -7,7 +7,8 @@
     "test": "tests"
   },
   "bin": {
-    "get-release-type": "./scripts/get-release-type.js"
+    "get-release-type": "./scripts/get-release-type.js",
+    "get-version": "./scripts/get-version.js"
   },
   "scripts": {
     "build": "echo",
@@ -25,4 +26,4 @@
   "dependencies": {
     "semver": "^5.5.0"
   }
-}
+}

scripts/get-version.js

@@ -0,0 +1,30 @@
+#!/usr/bin/env node
+
+'use strict'
+
+const util = require('util')
+const exec = util.promisify(require('child_process').exec)
+
+const whichPackage = process.argv[2]
+const whichVersion = process.argv[3]
+
+/**
+ * Get either the current or previous version of an NPM package
+ *
+ * @param {String} whichPackage NPM package to interrogate
+ * @param {?String} whichVersion If 'previous' then previous version, otherwise current
+ *
+ * @returns {String|undefined} Current or previous version of the NPM package
+ */
+async function getVersion(whichPackage, whichVersion) {
+    const {stdout, stderr} = await exec(`npm show ${whichPackage} versions --json`)
+
+    if (!stderr) {
+        const offset = (whichVersion === 'previous') ? 1 : 0
+        const versions = JSON.parse(stdout)
+
+        console.log(versions[versions.length - 1 - offset])
+    }
+}
+
+getVersion(whichPackage, whichVersion)

scripts/package-info.sh

@@ -77,11 +77,7 @@ function get_changelog_url() {
 # Get current package version
 #
 function get_current_version() {
-    local package=$1
-
-    get_versions "$package"
-
-    echo "${versions[${#versions[@]}-1]}"
+    get-version "$1"
 }
 
 #
@@ -159,11 +155,7 @@ function get_package_name () {
 # Get previous package version
 #
 function get_previous_version() {
-    local package=$1
-
-    get_versions "$package"
-
-    echo "${versions[${#versions[@]}-2]}"
+    get-version "$1" previous
 }
 
 #
@@ -175,30 +167,3 @@ function get_release_type() {
 
     get-release-type "$previous_version" "$current_version"
 }
-
-#
-# Get all published versions of package in NPM
-#
-function get_versions() {
-    # If "versions" is already populated don't need to populate it again
-    if [ -z ${versions+x} ];
-    then
-        local package=$1
-        local version_info_string
-        local version_info_string_array
-
-        version_info_string=$(npm view "$package" versions)
-        version_info_string_array=( $(echo "$version_info_string" | tr ' ' '\n') )
-
-        for ((i=0; i < ${#version_info_string_array[@]}; i++))
-        do
-            # if not first or last element, which are "[" and "]" (without quotes), respectively
-            if [ $i -ne 0 ] && [ $i -ne $((${#version_info_string_array[@]}-1)) ];
-            then
-                # is a global variable
-                # strips off apostrophes and commas
-                versions[$((i-1))]="${version_info_string_array[$i]//[\',]}"
-            fi
-        done
-    fi
-}