Allowed field pattern to be a string[] (#11)

Author: erikras

README.md

@@ -115,7 +115,7 @@ A calculation to perform, with an optional `isEqual` predicate to determine if a
 
 ### `FieldName: string`
 
-### `FieldPattern: FieldName | RegExp`
+### `FieldPattern: FieldName | RegExp | FieldName[]`
 
 A pattern to match a field with.
 

package.json

@@ -1,19 +1,19 @@
 {
   "name": "final-form-calculate",
   "version": "1.0.2",
-  "description":
-    "Decorator for calculating field values based on other field values in 🏁 Final Form",
+  "description": "Decorator for calculating field values based on other field values in 🏁 Final Form",
   "main": "dist/final-form-calculate.cjs.js",
   "jsnext:main": "dist/final-form-calculate.es.js",
   "module": "dist/final-form-calculate.es.js",
-  "files": ["dist"],
+  "files": [
+    "dist"
+  ],
   "scripts": {
     "start": "nps",
     "test": "nps test",
     "precommit": "lint-staged && npm start validate"
   },
-  "author":
-    "Erik Rasmussen <[email protected]> (http://github.com/erikras)",
+  "author": "Erik Rasmussen <[email protected]> (http://github.com/erikras)",
   "license": "MIT",
   "repository": {
     "type": "git",
@@ -62,7 +62,10 @@
     "final-form": ">=1.3.0"
   },
   "lint-staged": {
-    "*.{js,json,md,css}": ["prettier --write", "git add"]
+    "*.{js,json,md,css}": [
+      "prettier --write",
+      "git add"
+    ]
   },
   "bundlesize": [
     {

src/decorator.js

@@ -37,10 +37,12 @@ const createDecorator = (...calculations: Calculation[]): Decorator => (
           if (typeof field === 'string') {
             runUpdates(field, isEqual || tripleEquals, updates)
           } else {
-            // field is a regex
-            const regex = (field: RegExp)
+            // field is a either array or regex
+            const matches = Array.isArray(field)
+              ? name => ~field.indexOf(name)
+              : name => (field: RegExp).test(name)
             fields.forEach(fieldName => {
-              if (regex.test(fieldName)) {
+              if (matches(fieldName)) {
                 runUpdates(fieldName, isEqual || tripleEquals, updates)
               }
             })

src/decorator.test.js

@@ -89,6 +89,49 @@ describe('decorator', () => {
     expect(bar.mock.calls[1][0].value).toBe('bazbar')
   })
 
+  it('should update one field when another changes, using array of field names', () => {
+    const form = createForm({ onSubmit: onSubmitMock })
+    const spy = jest.fn()
+    const foo = jest.fn()
+    const bar = jest.fn()
+    form.subscribe(spy, { values: true })
+    form.registerField('foo', foo, { value: true })
+    form.registerField('bar', bar, { value: true })
+    const decorator = createDecorator({
+      field: ['cat', 'dog', 'rat', 'foo', 'hog'],
+      updates: {
+        bar: fooValue => `${fooValue}bar`
+      }
+    })
+    const unsubscribe = decorator(form)
+    expect(typeof unsubscribe).toBe('function')
+
+    expect(spy).toHaveBeenCalled()
+    expect(spy).toHaveBeenCalledTimes(1)
+    expect(spy.mock.calls[0][0].values).toEqual({})
+
+    expect(foo).toHaveBeenCalled()
+    expect(foo).toHaveBeenCalledTimes(1)
+    expect(foo.mock.calls[0][0].value).toBeUndefined()
+
+    expect(bar).toHaveBeenCalled()
+    expect(bar).toHaveBeenCalledTimes(1)
+    expect(bar.mock.calls[0][0].value).toBeUndefined()
+
+    // change foo (should trigger calculation on bar)
+    form.change('foo', 'baz')
+
+    expect(spy).toHaveBeenCalledTimes(3)
+    expect(spy.mock.calls[1][0].values).toEqual({ foo: 'baz' })
+    expect(spy.mock.calls[2][0].values).toEqual({ foo: 'baz', bar: 'bazbar' })
+
+    expect(foo).toHaveBeenCalledTimes(2)
+    expect(foo.mock.calls[1][0].value).toBe('baz')
+
+    expect(bar).toHaveBeenCalledTimes(2)
+    expect(bar.mock.calls[1][0].value).toBe('bazbar')
+  })
+
   it('should cease when unsubscribed', () => {
     const form = createForm({ onSubmit: onSubmitMock })
     const spy = jest.fn()

src/types.js.flow

@@ -1,6 +1,6 @@
 // @flow
 type FieldName = string
-export type FieldPattern = FieldName | RegExp
+export type FieldPattern = FieldName | RegExp | FieldName[]
 export type UpdatesByName = {
   [FieldName]: (value: any, allValues: ?Object) => any
 }