feat: add functions configuration API to @netlify/config (#2390)

* feat: add functions configuration API

* chore: remove dead branch and rename variables

* chore: improve validation of functions object

* chore: update ESLint exception

* chore: update property names

* feat: add validation for functions.*

* chore: rename fixtures

* chore: update property names

Author: eduardoboucas

packages/build/tests/commands/snapshots/tests.js.snap

@@ -81,6 +81,7 @@ Generated by [AVA](https://ava.li).
           "commandOrigin": "config",␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊

packages/build/tests/core/snapshots/tests.js.md

@@ -0,0 +1,53 @@
+'use strict'
+
+const isPlainObj = require('is-plain-obj')
+
+const configProperties = new Set(['external_node_modules', 'ignored_node_modules'])
+
+const WILDCARD_ALL = '*'
+
+const isConfigLeaf = (obj) => isPlainObj(obj) && Object.keys(obj).every(isConfigProperty)
+
+const isConfigProperty = (prop) => configProperties.has(prop)
+
+// Normalizes a functions configuration object, so that the first level of keys
+// represents function expressions mapped to a configuration object.
+//
+// Example input:
+// {
+//   "external_node_modules": ["one"],
+//   "my-function": { "external_node_modules": ["two"] }
+// }
+//
+// Example output:
+// {
+//   "*": { "external_node_modules": ["one"] },
+//   "my-function": { "external_node_modules": ["two"] }
+// }
+const normalize = (functions) => {
+  const normalizedFunctions = Object.keys(functions).reduce((result, prop) => {
+    // If `prop` is one of `configProperties``, we might be dealing with a
+    // top-level property (i.e. one that targets all functions). We consider
+    // that to be the case if the value is an object where all keys are also
+    // config properties. If not, it's simply a function with the same name
+    // as one of the config properties.
+    if (isConfigProperty(prop) && !isConfigLeaf(functions[prop])) {
+      return {
+        ...result,
+        [WILDCARD_ALL]: {
+          ...result[WILDCARD_ALL],
+          [prop]: functions[prop],
+        },
+      }
+    }
+
+    return {
+      ...result,
+      [prop]: functions[prop],
+    }
+  }, {})
+
+  return normalizedFunctions
+}
+
+module.exports = { normalize }

packages/build/tests/core/snapshots/tests.js.snap

@@ -1,17 +1,20 @@
 'use strict'
 
+const { normalize: normalizeFunctionsConfig } = require('./functions_config')
 const { deepMerge } = require('./utils/merge')
 const { removeFalsy } = require('./utils/remove_falsy')
 
 // Normalize configuration object
 const normalizeConfig = function (config) {
-  const { build, plugins, ...configA } = deepMerge(DEFAULT_CONFIG, config)
+  const { build, functions, plugins, ...configA } = deepMerge(DEFAULT_CONFIG, config)
+  const functionsA = normalizeFunctionsConfig(functions)
   const pluginsA = plugins.map(normalizePlugin)
-  return { ...configA, build, plugins: pluginsA }
+  return { ...configA, build, functions: functionsA, plugins: pluginsA }
 }
 
 const DEFAULT_CONFIG = {
   build: { environment: {} },
+  functions: {},
   plugins: [],
 }
 

packages/build/tests/env/snapshots/tests.js.snap

@@ -2,6 +2,16 @@
 
 const { normalize } = require('path')
 
+const isPlainObj = require('is-plain-obj')
+
+const isArrayOfObjects = function (value) {
+  return Array.isArray(value) && value.every(isPlainObj)
+}
+
+const isArrayOfStrings = function (value) {
+  return Array.isArray(value) && value.every(isString)
+}
+
 const isString = function (value) {
   return typeof value === 'string'
 }
@@ -37,4 +47,4 @@ const removeParentDots = function (path) {
 
 const PARENT_DOTS_REGEXP = /\.\.[/\\]/g
 
-module.exports = { isString, validProperties, insideRootCheck, removeParentDots }
+module.exports = { isArrayOfObjects, isArrayOfStrings, isString, validProperties, insideRootCheck, removeParentDots }

packages/build/tests/manifest/snapshots/tests.js.snap

@@ -1,9 +1,17 @@
+/* eslint-disable max-lines */
 'use strict'
 
 const isPlainObj = require('is-plain-obj')
 const validateNpmPackageName = require('validate-npm-package-name')
 
-const { isString, validProperties, insideRootCheck, removeParentDots } = require('./helpers')
+const {
+  isArrayOfObjects,
+  isArrayOfStrings,
+  isString,
+  validProperties,
+  insideRootCheck,
+  removeParentDots,
+} = require('./helpers')
 
 // List of validations performed on the configuration file.
 // Validation are performed in order: parent should be before children.
@@ -30,7 +38,7 @@ const PRE_CASE_NORMALIZE_VALIDATIONS = [
 const PRE_MERGE_VALIDATIONS = [
   {
     property: 'plugins',
-    check: (value) => Array.isArray(value) && value.every(isPlainObj),
+    check: isArrayOfObjects,
     message: 'must be an array of objects.',
     example: () => ({ plugins: [{ package: 'netlify-plugin-one' }, { package: 'netlify-plugin-two' }] }),
   },
@@ -60,6 +68,14 @@ const PRE_NORMALIZE_VALIDATIONS = [
     message: 'must be a string',
     example: () => ({ build: { command: 'npm run build' } }),
   },
+  {
+    property: 'functions',
+    check: isPlainObj,
+    message: 'must be an object.',
+    example: () => ({
+      functions: { external_node_modules: ['module-one', 'module-two'] },
+    }),
+  },
 ]
 
 const EXAMPLE_PORT = 80
@@ -149,6 +165,30 @@ const POST_NORMALIZE_VALIDATIONS = [
     ...insideRootCheck,
     example: (edgeHandlers) => ({ build: { edge_handlers: removeParentDots(edgeHandlers) } }),
   },
+  {
+    property: 'functions.*',
+    check: isPlainObj,
+    message: 'must be an object.',
+    example: (value, key, prevPath) => ({
+      functions: { [prevPath[1]]: { external_node_modules: ['module-one', 'module-two'] } },
+    }),
+  },
+  {
+    property: 'functions.*.external_node_modules',
+    check: isArrayOfStrings,
+    message: 'must be an array of strings.',
+    example: (value, key, prevPath) => ({
+      functions: { [prevPath[1]]: { external_node_modules: ['module-one', 'module-two'] } },
+    }),
+  },
+  {
+    property: 'functions.*.ignored_node_modules',
+    check: isArrayOfStrings,
+    message: 'must be an array of strings.',
+    example: (value, key, prevPath) => ({
+      functions: { [prevPath[1]]: { ignored_node_modules: ['module-one', 'module-two'] } },
+    }),
+  },
 ]
 
 module.exports = {
@@ -158,3 +198,4 @@ module.exports = {
   PRE_NORMALIZE_VALIDATIONS,
   POST_NORMALIZE_VALIDATIONS,
 }
+/* eslint-enable max-lines */

packages/config/src/functions_config.js

@@ -15,6 +15,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -109,6 +110,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -197,6 +199,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -288,6 +291,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -311,6 +315,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -399,6 +404,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -493,6 +499,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -611,6 +618,7 @@ Generated by [AVA](https://ava.li).
           "functions": "/file/path",␊
           "publish": "/file/path"␊
         },␊
+        "functions": {},␊
         "plugins": [␊
           {␊
             "inputs": {␊
@@ -761,6 +769,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -784,6 +793,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -872,6 +882,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -966,6 +977,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -1061,6 +1073,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -1180,6 +1193,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -1268,6 +1282,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -1367,6 +1382,7 @@ Generated by [AVA](https://ava.li).
           "functions": "/file/path",␊
           "publish": "/file/path"␊
         },␊
+        "functions": {},␊
         "plugins": [␊
           {␊
             "inputs": {␊
@@ -1512,6 +1528,7 @@ Generated by [AVA](https://ava.li).
           "environment": {},␊
           "publish": "/file/path"␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊

packages/config/src/normalize.js

@@ -27,6 +27,7 @@ Generated by [AVA](https://ava.li).
           "functions": "/file/path",␊
           "publish": "/file/path"␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -116,6 +117,7 @@ Generated by [AVA](https://ava.li).
           "commandOrigin": "config",␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -205,6 +207,7 @@ Generated by [AVA](https://ava.li).
           "commandOrigin": "config",␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -297,6 +300,7 @@ Generated by [AVA](https://ava.li).
           "functions": "/file/path",␊
           "publish": "/file/path"␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊

packages/config/src/validate/helpers.js

@@ -60,6 +60,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -216,6 +217,7 @@ Generated by [AVA](https://ava.li).
       "configPath": "/file/path",␊
       "buildDir": "/file/path",␊
       "config": {␊
+        "functions": {},␊
         "plugins": [],␊
         "build": {␊
           "environment": {}␊
@@ -240,6 +242,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊
@@ -330,6 +333,7 @@ Generated by [AVA](https://ava.li).
         "build": {␊
           "environment": {}␊
         },␊
+        "functions": {},␊
         "plugins": []␊
       },␊
       "configPath": "/file/path",␊