Provide friendlier error messages for [endpoint] (#2858)

Ref https://github.com/badges/shields/issues/2838#issuecomment-456594803

core/base-service/base.js

@@ -515,11 +515,20 @@ class BaseService {
     )
   }
 
-  static _validate(data, schema, { allowAndStripUnknownKeys = true } = {}) {
+  static _validate(
+    data,
+    schema,
+    {
+      prettyErrorMessage = 'invalid response data',
+      includeKeys = false,
+      allowAndStripUnknownKeys = true,
+    } = {}
+  ) {
     return validate(
       {
         ErrorClass: InvalidResponse,
-        prettyErrorMessage: 'invalid response data',
+        prettyErrorMessage,
+        includeKeys,
         traceErrorMessage: 'Response did not match schema',
         traceSuccessMessage: 'Response after validation',
         allowAndStripUnknownKeys,

core/base-service/validate.js

@@ -38,7 +38,7 @@ function validate(
     if (includeKeys) {
       const keys = error.details.map(({ path }) => path)
       if (keys) {
-        prettyMessage = `${prettyErrorMessage}: ${keys.join(',')}`
+        prettyMessage = `${prettyErrorMessage}: ${keys.join(', ')}`
       }
     }
 

core/base-service/validate.spec.js

@@ -89,7 +89,9 @@ describe('validate', function() {
         try {
           validate(
             { ...options, includeKeys: true },
-            { requiredString: ['this', "shouldn't", 'work'] },
+            {
+              requiredString: ['this', "shouldn't", 'work'],
+            },
             schema
           )
           expect.fail('Expected to throw')
@@ -107,12 +109,19 @@ describe('validate', function() {
   })
 
   it('allowAndStripUnknownKeys', function() {
-    expect(() =>
+    try {
       validate(
-        { ...options, allowAndStripUnknownKeys: false },
-        { requiredString: 'bar', extra: 'nonsense' },
+        { ...options, allowAndStripUnknownKeys: false, includeKeys: true },
+        { requiredString: 'bar', extra: 'nonsense', more: 'bogus' },
         schema
       )
-    ).to.throw(InvalidParameter, '"extra" is not allowed')
+      expect.fail('Expected to throw')
+    } catch (e) {
+      expect(e).to.be.an.instanceof(InvalidParameter)
+      expect(e.message).to.equal(
+        'Invalid Parameter: "extra" is not allowed. "more" is not allowed'
+      )
+      expect(e.prettyMessage).to.equal(`${prettyErrorMessage}: extra, more`)
+    }
   })
 })

services/endpoint/endpoint.service.js

@@ -123,6 +123,8 @@ module.exports = class Endpoint extends BaseJsonService {
     })
     // Override the validation options because we want to reject unknown keys.
     const validated = this.constructor._validate(json, endpointSchema, {
+      prettyErrorMessage: 'invalid properties',
+      includeKeys: true,
       allowAndStripUnknownKeys: false,
     })
 

services/endpoint/endpoint.tester.js

@@ -146,7 +146,10 @@ t.create('Invalid schema (mocked)')
         schemaVersion: -1,
       })
   )
-  .expectJSON({ name: 'custom badge', value: 'invalid response data' })
+  .expectJSON({
+    name: 'custom badge',
+    value: 'invalid properties: schemaVersion',
+  })
 
 t.create('Invalid schema (mocked)')
   .get('.json?url=https://example.com/badge')
@@ -161,7 +164,10 @@ t.create('Invalid schema (mocked)')
         bogus: true,
       })
   )
-  .expectJSON({ name: 'custom badge', value: 'invalid response data' })
+  .expectJSON({
+    name: 'custom badge',
+    value: 'invalid properties: extra, bogus',
+  })
 
 t.create('User color overrides success color')
   .get('.json?url=https://example.com/badge&colorB=101010&style=_shields_test')