Merge 615ea23 into 004d80e

README.md

@@ -47,6 +47,8 @@ console.log(config)
 
 see [DotenvConfigOptions](https://github.com/motdotla/dotenv#options)
 
+### Custom ajv instance
+
 Optionally, the user can supply their own ajv instance:
 
 ```js
@@ -81,6 +83,27 @@ console.log(config)
 // output: { PORT: 3000 }
 ```
 
+It is possible to enhance the default ajv instance providing the `customOptions` function parameter.
+This example shows how to use the `format` keyword in your schemas.
+
+```js
+const config = envSchema({
+  schema: schema,
+  data: data,
+  dotenv: true,
+  ajv: {
+    customOptions (ajvInstance) {
+      require('ajv-formats')(ajvInstance)
+      return ajvInstance
+    }
+  }
+})
+```
+
+Note that it is mandatory returning the ajv instance.
+
+### Fluent-Schema API
+
 It is also possible to use [fluent-json-schema](http://npm.im/fluent-json-schema):
 
 ```js

index.js

@@ -46,14 +46,7 @@ const optsSchema = {
   }
 }
 
-const sharedAjvInstance = new Ajv({
-  allErrors: true,
-  removeAdditional: true,
-  useDefaults: true,
-  coerceTypes: true,
-  allowUnionTypes: true,
-  keywords: [separator]
-})
+const sharedAjvInstance = getDefaultInstance()
 
 const optsSchemaValidator = sharedAjvInstance.compile(optsSchema)
 
@@ -93,7 +86,7 @@ function loadAndValidateEnvironment (_opts) {
   const merge = {}
   data.forEach(d => Object.assign(merge, d))
 
-  const ajv = opts.ajv == null ? sharedAjvInstance : opts.ajv
+  const ajv = chooseAjvInstance(sharedAjvInstance, opts.ajv)
 
   const valid = ajv.validate(schema, merge)
   if (!valid) {
@@ -105,6 +98,30 @@ function loadAndValidateEnvironment (_opts) {
   return merge
 }
 
+function chooseAjvInstance (defaultInstance, ajvOpts) {
+  if (!ajvOpts) {
+    return defaultInstance
+  } else if (typeof ajvOpts === 'object' && typeof ajvOpts.customOptions === 'function') {
+    const ajv = ajvOpts.customOptions(getDefaultInstance())
+    if (!ajv) {
+      throw new Error('customOptions function must return an instance of Ajv')
+    }
+    return ajv
+  }
+  return ajvOpts
+}
+
+function getDefaultInstance () {
+  return new Ajv({
+    allErrors: true,
+    removeAdditional: true,
+    useDefaults: true,
+    coerceTypes: true,
+    allowUnionTypes: true,
+    keywords: [separator]
+  })
+}
+
 module.exports = loadAndValidateEnvironment
 module.exports.default = loadAndValidateEnvironment
 module.exports.envSchema = loadAndValidateEnvironment

package.json

@@ -28,6 +28,7 @@
   },
   "homepage": "https://github.com/fastify/env-schema#readme",
   "devDependencies": {
+    "ajv-formats": "^2.1.1",
     "fluent-json-schema": "^3.0.0",
     "pre-commit": "^1.2.2",
     "snazzy": "^9.0.0",

test/custom-ajv.test.js

@@ -296,3 +296,51 @@ const strictValidator = new Ajv({
     makeTest(t, options, testConf.isOk, testConf.confExpected, testConf.errorMessage)
   })
 })
+
+t.test('ajv enhancement', t => {
+  t.plan(2)
+  const testCase = {
+    schema: {
+      type: 'object',
+      required: ['MONGODB_URL'],
+      properties: {
+        MONGODB_URL: {
+          type: 'string',
+          format: 'uri'
+        }
+      }
+    },
+    data: [{ PORT: 3333 }, { MONGODB_URL: 'mongodb://localhost/pippo' }],
+    isOk: true,
+    confExpected: {
+      MONGODB_URL: 'mongodb://localhost/pippo'
+    }
+  }
+
+  t.test('return', t => {
+    const options = {
+      schema: testCase.schema,
+      data: testCase.data,
+      ajv: {
+        customOptions (ajvInstance) {
+          require('ajv-formats')(ajvInstance)
+          return ajvInstance
+        }
+      }
+    }
+    makeTest(t, options, testCase.isOk, testCase.confExpected)
+  })
+
+  t.test('no return', t => {
+    const options = {
+      schema: testCase.schema,
+      data: testCase.data,
+      ajv: {
+        customOptions (ajvInstance) {
+          // do nothing
+        }
+      }
+    }
+    makeTest(t, options, false, undefined, 'customOptions function must return an instance of Ajv')
+  })
+})