feat: Support static snapshots in .percy.yml configuration file

src/commands/snapshot.ts

@@ -2,6 +2,7 @@ import {flags} from '@oclif/command'
 import Constants from '../services/constants'
 import {StaticSnapshotOptions} from '../services/static-snapshot-options'
 import StaticSnapshotService from '../services/static-snapshot-service'
+import configuration, {StaticSiteSnapshotConfiguration} from '../utils/configuration'
 import logger from '../utils/logger'
 import PercyCommand from './percy-command'
 
@@ -60,18 +61,26 @@ export default class Snapshot extends PercyCommand {
     const port = flags.port as number
     const staticServerPort = port + 1
     const networkIdleTimeout = flags['network-idle-timeout'] as number
-    const baseUrl = flags['base-url'] as string
-    const rawIgnoreGlob = flags['ignore-files'] as string
-    const rawSnapshotGlob = flags['snapshot-files'] as string
 
-    const snapshotGlobs = rawSnapshotGlob.split(',')
-
-    const ignoreGlobs = rawIgnoreGlob ? rawIgnoreGlob.split(',') : []
+    const baseUrlFlag = flags['base-url'] as string
+    const rawIgnoreGlobFlag = flags['ignore-files'] as string
+    const rawSnapshotGlobFlag = flags['snapshot-files'] as string
 
     // exit gracefully if percy will not run
     if (!this.percyWillRun()) { this.exit(0) }
 
-    // check that the base url passed in starts with a slash and exit if it is missing
+    // read configurations from the percy.yml file
+    const staticSiteConfiguration = (configuration().static_site || {}) as StaticSiteSnapshotConfiguration
+    const baseUrl = staticSiteConfiguration['base-url'] || baseUrlFlag
+    const rawSnapshotGlobs = staticSiteConfiguration['snapshot-files'] || rawSnapshotGlobFlag
+    const rawIgnoreGlobs = staticSiteConfiguration['ignore-files'] || rawIgnoreGlobFlag
+
+    const snapshotGlobs = rawSnapshotGlobs.split(',')
+
+    // if it is an empty string then convert it to an empty array instead of an array of an empty string
+    const ignoreGlobs = rawIgnoreGlobs ? rawIgnoreGlobs.split(',') : []
+
+    // check that base url starts with a slash and exit if it is missing
     if (baseUrl[0] !== '/') {
       logger.warn('The base-url flag must begin with a slash.')
       this.exit(1)

src/utils/configuration.ts

@@ -7,9 +7,16 @@ export interface SnapshotConfiguration {
   'min-height'?: number,
 }
 
+export interface StaticSiteSnapshotConfiguration {
+  'base-url'?: string,
+  'snapshot-files'?: string,
+  'ignore-files'?: string,
+}
+
 export interface Configuration {
   version: number,
   snapshot: SnapshotConfiguration
+  static_site: StaticSiteSnapshotConfiguration
 }
 
 const configuration = (relativePath = '.percy.yml'): Configuration => {
@@ -22,7 +29,9 @@ const configuration = (relativePath = '.percy.yml'): Configuration => {
     // in a chain. snapshot specific options -> agent configuration -> default values
 
     const defaultConfiguration: Configuration = {
-      version: 1.0, snapshot: {},
+      version: 1.0,
+      snapshot: {},
+      static_site: {},
     }
 
     return defaultConfiguration

test/support/.percy.yml

@@ -2,3 +2,7 @@ version: 1
 snapshot:
   widths: [375, 1280]
   min-height: 1024
+static_site:
+  base-url: /blog
+  snapshot-files: '**/*.html'
+  ignore-files: '**/*.htm'

test/utils/configuration.test.ts

@@ -8,11 +8,14 @@ describe('Configuration', () => {
     expect(subject.version).to.eql(1)
     expect(subject.snapshot.widths).to.eql([375, 1280])
     expect(subject.snapshot['min-height']).to.eql(1024)
+    expect(subject.static_site['base-url']).to.eql('/blog')
+    expect(subject.static_site['snapshot-files']).to.eql('**/*.html')
+    expect(subject.static_site['ignore-files']).to.eql('**/*.htm')
   })
 
   it('gracefully handles a missing file', () => {
     const subject = configuration('test/support/.file-does-not-exist.yml')
 
-    expect(subject).to.eql({version: 1.0, snapshot: {}})
+    expect(subject).to.eql({version: 1.0, snapshot: {}, static_site: {}})
   })
 })