Add custom handlebars helpers

__tests__/fixtures/slack.yml

@@ -1,7 +1,7 @@
 username: GitHub-CI
 icon_url: https://octodex.github.com/images/mona-the-rivetertocat.png
 
-pretext: Triggered via {{eventName}} by {{actor}} {{or action "action"}} {{ref}} `{{diffRef}}`
+pretext: Triggered via {{eventName}} by {{actor}} {{default action "action"}} {{ref}} `{{diffRef}}`
 title: GitHub Actions
 title_link: https://support.github.com
 
@@ -11,7 +11,7 @@ text: |
   {{#if payload.commits}}
   *Commits*
   {{#each payload.commits}}
-  <{{this.url}}|`{{limitTo this.id 8}}`> - {{this.message}}
+  <{{this.url}}|`{{truncate this.id 8}}`> - {{this.message}}
   {{/each}}
   {{/if}}
 

__tests__/handlebars.test.ts

@@ -0,0 +1,157 @@
+import Handlebars from '../src/handlebars'
+
+const data = {
+  foo: 'bar',
+  fu: 'bar',
+  obj: {
+    a: 'b',
+    c: 123,
+    d: ['x', 'y', 'z']
+  },
+  text: 'this is a long line of text',
+  uuid: 'CFE20509-E7CF-4401-9733-7615EF3E8A25',
+  want: 0,
+  t: true,
+  f: false,
+  empty: [],
+  commits: ['088fcd5a5bc73a6733edcc58d0d30869ddbe2e2f'],
+  numbers: [1, 2, 3, 4],
+  letters: ['abc', 'def', 'ghi'],
+  foobars: [
+    {foo: true, bar: 1},
+    {foo: false, bar: 3},
+    {foo: true, bar: 3}
+  ],
+  attendees: ['dave', 'mike', 'jane', 'betty'],
+  items: [1, 2, 3]
+}
+
+// utilities
+test('json stringify', () => {
+  const template = Handlebars.compile('{{{json obj}}}')
+  const text = template(data)
+  expect(text).toStrictEqual('{"a":"b","c":123,"d":["x","y","z"]}')
+})
+
+test('truncate uuid', () => {
+  const template = Handlebars.compile('{{truncate uuid 8}}')
+  const text = template(data)
+  expect(text).toStrictEqual('CFE20509')
+})
+
+test('default is not needed', () => {
+  const template = Handlebars.compile('{{default want "fallback"}}')
+  const text = template(data)
+  expect(text).toStrictEqual('0')
+})
+
+test('default is needed', () => {
+  const template = Handlebars.compile('{{default fallback "fallback"}}')
+  const text = template(data)
+  expect(text).toStrictEqual('fallback')
+})
+
+test('pluralize empty list', () => {
+  const template = Handlebars.compile('{{pluralize empty}}')
+  const text = template(data)
+  expect(text).toStrictEqual('no items')
+})
+
+test('pluralize commits', () => {
+  const template = Handlebars.compile('{{pluralize commits "commit"}}')
+  const text = template(data)
+  expect(text).toStrictEqual('1 commit')
+})
+
+test('pluralize attendees', () => {
+  const template = Handlebars.compile('{{pluralize attendees "attendee"}}')
+  const text = template(data)
+  expect(text).toStrictEqual('4 attendees')
+})
+
+test('pluralize people', () => {
+  const template = Handlebars.compile('{{pluralize attendees "person" "people"}}')
+  const text = template(data)
+  expect(text).toStrictEqual('4 people')
+})
+
+// equality
+test('eq is true', () => {
+  const template = Handlebars.compile('{{#if (eq foo fu)}}yes{{else}}no{{/if}}')
+  const text = template(data)
+  expect(text).toStrictEqual('yes')
+})
+
+test('eq is false', () => {
+  const template = Handlebars.compile('{{#if (eq foo "foo")}}yes{{else}}no{{/if}}')
+  const text = template(data)
+  expect(text).toStrictEqual('no')
+})
+
+test('neq is true', () => {
+  const template = Handlebars.compile('{{#if (neq foo fu)}}yes{{else}}no{{/if}}')
+  const text = template(data)
+  expect(text).toStrictEqual('no')
+})
+
+test('neq is false', () => {
+  const template = Handlebars.compile('{{#if (neq foo "foo")}}yes{{else}}no{{/if}}')
+  const text = template(data)
+  expect(text).toStrictEqual('yes')
+})
+
+// boolean operators
+test('not false', () => {
+  const template = Handlebars.compile('{{#if (not f)}}yes{{else}}no{{/if}}')
+  const text = template(data)
+  expect(text).toStrictEqual('yes')
+})
+
+test('not true', () => {
+  const template = Handlebars.compile('{{#if (not t)}}yes{{else}}no{{/if}}')
+  const text = template(data)
+  expect(text).toStrictEqual('no')
+})
+
+test('not false and (true or false)', () => {
+  const template = Handlebars.compile('{{#if (and (not f) (or t f))}}yes{{else}}no{{/if}}')
+  const text = template(data)
+  expect(text).toStrictEqual('yes')
+})
+
+test('or is true', () => {
+  const template = Handlebars.compile('{{#if (or t f)}}yes{{else}}no{{/if}}')
+  const text = template(data)
+  expect(text).toStrictEqual('yes')
+})
+
+test('and is false', () => {
+  const template = Handlebars.compile('{{#if (and t f)}}yes{{else}}no{{/if}}')
+  const text = template(data)
+  expect(text).toStrictEqual('no')
+})
+
+// conditionals
+test('#ifeq is true', () => {
+  const template = Handlebars.compile('{{#ifeq foo fu}}yes{{else}}no{{/ifeq}}')
+  const text = template(data)
+  expect(text).toStrictEqual('yes')
+})
+
+test('#ifeq is false', () => {
+  const template = Handlebars.compile('{{#ifeq foo "foo"}}yes{{else}}no{{/ifeq}}')
+  const text = template(data)
+  expect(text).toStrictEqual('no')
+})
+
+test('#ifneq is true', () => {
+  const template = Handlebars.compile('{{#ifneq foo fu}}yes{{else}}no{{/ifneq}}')
+  const text = template(data)
+  expect(text).toStrictEqual('no')
+})
+
+test('#ifneq is false', () => {
+  const template = Handlebars.compile('{{#ifneq foo "foo"}}yes{{else}}no{{/ifneq}}')
+  const text = template(data)
+  expect(text).toStrictEqual('yes')
+})

src/handlebars.ts

@@ -0,0 +1,41 @@
+import Handlebars from 'handlebars'
+
+// utilities
+Handlebars.registerHelper('json', value => new Handlebars.SafeString(JSON.stringify(value)))
+
+Handlebars.registerHelper('truncate', (text, size) => text.substring(0, size))
+
+Handlebars.registerHelper('default', (want, fallback) => want ?? fallback)
+
+Handlebars.registerHelper('pluralize', (items, ...args) => {
+  const count = items.length
+  const singular = args.length === 1 ? 'item' : args[0]
+  const plural = args.length === 3 ? args[1] : `${singular}s`
+
+  if (count === 0) return `no ${plural}`
+  if (count === 1) return `1 ${singular}`
+  return `${count} ${plural}`
+})
+
+// equality
+Handlebars.registerHelper('eq', (a, b) => a === b)
+
+Handlebars.registerHelper('neq', (a, b) => a !== b)
+
+// logical operators
+Handlebars.registerHelper('not', a => !a)
+
+Handlebars.registerHelper('and', (a, b) => a && b)
+
+Handlebars.registerHelper('or', (a, b) => a || b)
+
+// conditionals
+Handlebars.registerHelper('ifeq', (a, b, opts) => {
+  return a === b ? opts.fn(this) : opts.inverse(this) // eslint-disable-line no-invalid-this
+})
+
+Handlebars.registerHelper('ifneq', (a, b, opts) => {
+  return a !== b ? opts.fn(this) : opts.inverse(this) // eslint-disable-line no-invalid-this
+})
+
+export default Handlebars

src/slack.ts

@@ -2,7 +2,7 @@ import * as core from '@actions/core'
 import * as github from '@actions/github'
 import {IncomingWebhook, IncomingWebhookResult} from '@slack/webhook'
 import {EventPayloads} from '@octokit/webhooks'
-import Handlebars from 'handlebars'
+import Handlebars from './handlebars'
 
 interface ColorOptions {
   success?: string | undefined
@@ -155,18 +155,6 @@ export async function send(
     return stepIcon(status, opts?.icons)
   })
 
-  Handlebars.registerHelper('json', function (context) {
-    return JSON.stringify(context)
-  })
-
-  Handlebars.registerHelper('limitTo', function (text, size) {
-    return text.substring(0, size)
-  })
-
-  Handlebars.registerHelper('or', function (op1, op2) {
-    return op1 || op2
-  })
-
   const pretextTemplate = Handlebars.compile(opts?.pretext || '')
   const titleTemplate = Handlebars.compile(opts?.title || '')