New: command to check Node version

Author: mysticatea

README.md

@@ -35,16 +35,32 @@ $ npm install --save-dev if-node-version
 ```
 Usage:
     $ if-node-version <VersionRange> <Command> [...args]
+
+        Run a shell command if it's on the node of specified versions.
+        Otherwise, do nothing.
+
+        Exit code is the exit code of the <Command>.
+
+    $ if-node-version <VersionRange>
+
+        Check if it's on the node of specified versions.
+
+        Exit code is 0 if it's on the node of specified versions.
+        Otherwise, exit code is 1.
+
     $ if-node-version --help
+
+        Show this help text.
+
     $ if-node-version --version
 
-    Run a shell command if it's on the node of specified versions.
+        Show the version number of `if-node-version` command.
 
 Parameters:
-    <VersionRange> .... A text which specifies the version range of Node.js.
+    <VersionRange> .... A text which specifies the version range of Node.js
                         This text format is defined by node-semver module:
                         https://www.npmjs.com/package/semver#ranges
-    <Command> ......... A shell command.
+    <Command> ......... The shell command to execute.
     [...args] ......... Parameters of the shell command.
 
 Examples:
@@ -86,6 +102,15 @@ This function returns the object as same as [child_process.spawnSync].
 Welcome your contributions!<br>
 Please use GitHub's issues/PRs.
 
+### Tools to develop
+
+- `npm install` installs dependencies.
+- `npm test` runs tests and measures coverage.
+- `npm run coverage` opens the coverage result of `npm test`.
+- `npm run clean` removes the coverage result of `npm test`.
+- `npm run lint` analyzes codes by ESLint.
+- `npm run watch` runs tests (without coverage measurement) when source code is modified.
+
 
 [npm]: https://www.npmjs.com/
 [npm-scripts]: https://docs.npmjs.com/misc/scripts

bin/help.txt

@@ -1,10 +1,26 @@
 
 Usage:
     $ if-node-version <VersionRange> <Command> [...args]
+
+        Run a shell command if it's on the node of specified versions.
+        Otherwise, do nothing.
+
+        Exit code is the exit code of the <Command>.
+
+    $ if-node-version <VersionRange>
+
+        Check if it's on the node of specified versions.
+
+        Exit code is 0 if it's on the node of specified versions.
+        Otherwise, exit code is 1.
+
     $ if-node-version --help
+
+        Show this help text.
+
     $ if-node-version --version
 
-    Run a shell command if it's on the node of specified versions.
+        Show the version number of `if-node-version` command.
 
 Parameters:
     <VersionRange> .... A text which specifies the version range of Node.js

bin/index.js

@@ -10,7 +10,7 @@
 // Requirements
 //------------------------------------------------------------------------------
 
-var spawnIfNodeVersionSatisfies = require("../lib")
+var spawn = require("../lib")
 
 //------------------------------------------------------------------------------
 // Main
@@ -24,20 +24,24 @@ var args = argv.slice(4)
 
 if (versionRange === "--help" || versionRange === "-h") {
     require("./help").printHelp(process.stdout)
-    return
+    process.exit(0)
 }
 
 if (versionRange === "--version" || versionRange === "-v") {
     require("./version").printVersion(process.stdout)
-    return
+    process.exit(0)
 }
 
-if (argv.length < 4) {
+if (!versionRange) {
     require("./help").printHelp(process.stderr)
     process.exit(1)
 }
 
-var cp = spawnIfNodeVersionSatisfies(
+if (!command) {
+    process.exit(spawn.isNodeVersionSatisfies(versionRange) ? 0 : 1)
+}
+
+var cp = spawn(
     versionRange,
     command,
     args,

lib/index.js

@@ -20,11 +20,7 @@ function isNodeVersionSatisfies(range) {
     return semver.satisfies(process.versions.node, range)
 }
 
-//------------------------------------------------------------------------------
-// Public Interface
-//------------------------------------------------------------------------------
-
-module.exports = function spawnIfNodeVersionSatisfies(
+function spawnIfNodeVersionSatisfies(
     versionRange,
     command,
     args,
@@ -36,7 +32,7 @@ module.exports = function spawnIfNodeVersionSatisfies(
     return null
 }
 
-module.exports.sync = function spawnIfNodeVersionSatisfiesSync(
+function spawnIfNodeVersionSatisfiesSync(
     versionRange,
     command,
     args,
@@ -47,3 +43,11 @@ module.exports.sync = function spawnIfNodeVersionSatisfiesSync(
     }
     return null
 }
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+module.exports = spawnIfNodeVersionSatisfies
+module.exports.sync = spawnIfNodeVersionSatisfiesSync
+module.exports.isNodeVersionSatisfies = isNodeVersionSatisfies

test/api.js

@@ -25,7 +25,7 @@ var runSync = api.runSync
 // Test
 //------------------------------------------------------------------------------
 
-describe("Under Node.js v" + version + ",", function() {
+describe("[Node API] Under Node.js v" + version + ",", function() {
     var ranges = [
         ">=0.10",
         ">=0.12",

test/cli.js

@@ -25,7 +25,7 @@ var runToCheck = cli.runToCheck
 // Test
 //------------------------------------------------------------------------------
 
-describe("If no argument,", function() {
+describe("[CLI Command] If no argument,", function() {
     var result = null
 
     before(function() {
@@ -48,7 +48,7 @@ describe("If no argument,", function() {
     })
 })
 
-describe("If '--help' is given,", function() {
+describe("[CLI Command] If '--help' is given,", function() {
     var result = null
 
     before(function() {
@@ -70,7 +70,7 @@ describe("If '--help' is given,", function() {
     })
 })
 
-describe("If '-h' is given,", function() {
+describe("[CLI Command] If '-h' is given,", function() {
     var result = null
 
     before(function() {
@@ -92,7 +92,7 @@ describe("If '-h' is given,", function() {
     })
 })
 
-describe("If '--version' is given,", function() {
+describe("[CLI Command] If '--version' is given,", function() {
     var result = null
 
     before(function() {
@@ -115,7 +115,7 @@ describe("If '--version' is given,", function() {
     })
 })
 
-describe("Under Node.js v" + version + ",", function() {
+describe("[CLI Command] Under Node.js v" + version + ",", function() {
     var ranges = [
         ">=0.10",
         ">=0.12",
@@ -186,6 +186,35 @@ describe("Under Node.js v" + version + ",", function() {
                     })
                 }
             })
+
+            describe("with no command,", function() {
+                var result = null
+
+                before(function() {
+                    return run([range]).then(function(ret) {
+                        result = ret
+                    })
+                })
+
+                it("should not output to stdout", function() {
+                    assert(result.stdout === "")
+                })
+
+                it("should not output to stderr", function() {
+                    assert(result.stderr === "")
+                })
+
+                if (semver.satisfies(version, range)) {
+                    it("should exit with zero", function() {
+                        assert(result.exitCode === 0)
+                    })
+                }
+                else {
+                    it("should exit with one", function() {
+                        assert(result.exitCode === 1)
+                    })
+                }
+            })
         })
     })
 })