feat: add API method to form good json block, close #4

Author: bahmutov

README.md

@@ -70,6 +70,25 @@ commit message embeds the following JSON block
 and the CI has command `run-if echo Foo is \\$FOO`, then on Windows CI it will print
 `Foo is bar` and on other platforms it will skip this step.
 
+## API
+
+You can form good Json object to be included in markdown `json` block in the body of
+the commit message using provided function
+
+```js
+const {getInstallJson} = require('commit-message-install')
+// package(s), env, platform
+const json = getInstallJson('foo', {foo: 42}, 'linux')
+// returns an object
+// {platform: "linux", env: {foo: 42}, packages: "foo"}
+```
+
+You can pass individual package name like `debug` or several as a single string `debug chalk`
+or a list `['debug', 'chalk']`
+
+You can pass for platform either individual `os.platform()` or a "*"" for all, and even
+several platforms like `win32,linux` or `linux|darwin`.
+
 ## Debugging
 
 - Run this tool with `DEBUG=commit-message-install` environment variable set

__snapshots__/commit-message-install-spec.js

@@ -1,7 +1,29 @@
-exports['commit-message-install getJsonBlock finds single json block at start 1'] = {
-  "foo": "bar"
+exports['commit-message-install getInstallJson sets properties and all platforms 1'] = {
+  "platform": "*",
+  "env": {
+    "foo": 42
+  },
+  "packages": "debug"
 }
 
+exports['commit-message-install getInstallJson sets given platform 1'] = {
+  "platform": "linux",
+  "env": {
+    "foo": 42
+  },
+  "packages": "debug"
+}
+
+exports['commit-message-install getInstallJson sets several modules 1'] = {
+  "platform": "linux",
+  "env": {},
+  "packages": "debug chalk"
+}
+
+exports['commit-message-install gets last commit message returns just the body of the commit message 1'] = `
+message body
+`
+
 exports['commit-message-install isPlatformAllowed compares platforms isPlatformAllowed 1'] = {
   "name": "isPlatformAllowed",
   "behavior": [
@@ -81,14 +103,14 @@ exports['commit-message-install getCommand removes --file and its argument 1'] =
   "command": "echo foo bar"
 }
 
+exports['commit-message-install getJsonBlock finds single json block at start 1'] = {
+  "foo": "bar"
+}
+
 exports['commit-message-install getJsonBlock finds single json block 1'] = {
   "foo": "bar"
 }
 
 exports['commit-message-install getJsonBlock returns first found json block 1'] = {
   "foo": "bar"
 }
-
-exports['commit-message-install gets last commit message returns just the body of the commit message 1'] = `
-message body
-`

src/commit-message-install-spec.js

@@ -22,6 +22,22 @@ describe('commit-message-install', () => {
     })
   })
 
+  context('getInstallJson', () => {
+    const { getInstallJson } = require('.')
+
+    it('sets properties and all platforms', () => {
+      snapshot(getInstallJson('debug', { foo: 42 }, '*'))
+    })
+
+    it('sets given platform', () => {
+      snapshot(getInstallJson('debug', { foo: 42 }, 'linux'))
+    })
+
+    it('sets several modules', () => {
+      snapshot(getInstallJson(['debug', 'chalk'], {}, 'linux'))
+    })
+  })
+
   context('isPlatformAllowed', () => {
     const { isPlatformAllowed } = require('.')
 

src/index.js

@@ -106,18 +106,20 @@ function runIf (command, json) {
   la(is.unemptyString(command), 'missing command to run', command)
   la(isRunIf(json), 'invalid runIf json', json)
 
-  if (!isPlatformAllowed(json.platform, os.platform())) {
+  const osPlatform = os.platform()
+  if (!isPlatformAllowed(json.platform, osPlatform)) {
     console.log('Required platform: %s', chalk.green(json.platform))
-    console.log('Current platform: %s', chalk.red(os.platform()))
+    console.log('Current platform: %s', chalk.red(osPlatform))
     console.log('skipping command ⏩  %s', command)
     return Promise.resolve()
   }
+  console.log('Platform %s is allowed', chalk.green(osPlatform))
 
   const options = {
     env: json.env,
     stdio: 'inherit'
   }
-  return execa.shell(command, options).then(prop('stdout'))
+  return execa.shell(command, options)
 }
 
 function npmInstall (json) {
@@ -127,23 +129,58 @@ function npmInstall (json) {
   }
   la(isNpmInstall(json), 'invalid JSON to install format', json)
 
-  if (!isPlatformAllowed(json.platform, os.platform())) {
+  const osPlatform = os.platform()
+  if (!isPlatformAllowed(json.platform, osPlatform)) {
     console.log('Required platform: %s', chalk.green(json.platform))
-    console.log('Current platform: %s', chalk.red(os.platform()))
+    console.log('Current platform: %s', chalk.red(osPlatform))
     console.log('skipping NPM install')
     return Promise.resolve()
   }
+  console.log('Platform %s is allowed', chalk.green(osPlatform))
 
   const env = json.env || {}
   console.log('installing', json.packages)
   if (is.not.empty(env)) {
     console.log('with extra environment variables')
     console.log(env)
   }
+  if (json.packages.indexOf(',') !== -1) {
+    console.log('warning: list of packages includes commas')
+    console.log('npm install might not work!')
+    console.log(json.packages)
+  }
   return execa('npm', ['install', json.packages], {
     env,
     stdio: 'inherit'
-  }).then(prop('stdout'))
+  })
+}
+
+// forms JSON object that can be parsed later
+function getInstallJson (packages, env = {}, platform = os.platform()) {
+  la(
+    is.unemptyString(packages) || is.strings(packages),
+    'invalid package / list of packages',
+    packages
+  )
+  la(is.object(env), 'invalid env object', env)
+  if (is.strings(packages)) {
+    packages = packages.join(' ')
+  }
+  la(is.unemptyString(platform), 'missing platform', platform)
+
+  const json = {
+    platform,
+    env,
+    packages
+  }
+  la(
+    isNpmInstall(json),
+    'formed invalid json object',
+    json,
+    'from arguments',
+    arguments
+  )
+  return json
 }
 
 module.exports = {
@@ -152,5 +189,6 @@ module.exports = {
   runIf,
   isPlatformAllowed,
   getJsonBlock,
-  npmInstall
+  npmInstall,
+  getInstallJson
 }