feat(schema): improve enum validation

package.json

@@ -64,7 +64,7 @@
     "abort-controller": "^3.0.0",
     "ajv": "^6.7",
     "ajv-oai": "^1.1.1",
-    "better-ajv-errors": "0.6.6",
+    "better-ajv-errors": "^0.6.7",
     "chalk": "^2.4.2",
     "deprecated-decorator": "^0.1.6",
     "jsonpath-plus": "~1.0",

src/functions/__tests__/schema.test.ts

@@ -246,4 +246,34 @@ describe('schema', () => {
 
     expect(runSchema.bind(null, 'd', testSchema)).not.toThrow();
   });
+
+  test('reports pretty enum errors for primitive values', () => {
+    const testSchema: JSONSchema6 = {
+      $schema: `http://json-schema.org/draft-06/schema#`,
+      type: 'string',
+      enum: ['foo', 'bar'],
+    };
+
+    expect(runSchema('baz', testSchema)).toEqual([
+      {
+        message: 'should be equal to one of the allowed values: foo, bar. Did you mean bar?',
+        path: [],
+      },
+    ]);
+  });
+
+  test('reports slightly less pretty enum errors for primitive values that are not similar to any values in enum', () => {
+    const testSchema: JSONSchema6 = {
+      $schema: `http://json-schema.org/draft-06/schema#`,
+      type: 'string',
+      enum: ['foo', 'bar'],
+    };
+
+    expect(runSchema('three', testSchema)).toEqual([
+      {
+        message: 'should be equal to one of the allowed values: foo, bar',
+        path: [],
+      },
+    ]);
+  });
 });

src/functions/schema.ts

@@ -1,11 +1,13 @@
 import { decodePointerFragment } from '@stoplight/json';
+import { Optional } from '@stoplight/types';
 import * as AJV from 'ajv';
 import { ValidateFunction } from 'ajv';
 import * as jsonSpecv4 from 'ajv/lib/refs/json-schema-draft-04.json';
 import * as jsonSpecv6 from 'ajv/lib/refs/json-schema-draft-06.json';
 import * as jsonSpecv7 from 'ajv/lib/refs/json-schema-draft-07.json';
 import { IOutputError } from 'better-ajv-errors';
 import { JSONSchema4, JSONSchema6 } from 'json-schema';
+import { escapeRegExp } from 'tslint/lib/utils';
 import { IFunction, IFunctionResult, ISchemaOptions } from '../types';
 const oasFormatValidator = require('ajv-oai/lib/format-validator');
 const betterAjvErrors = require('better-ajv-errors/lib/modern');
@@ -76,7 +78,11 @@ const validators = new class extends WeakMap<JSONSchema4 | JSONSchema6, Validate
   }
 }();
 
-const cleanAJVErrorMessage = (message: string) => message.trim().replace(/^[^:]*:\s*/, '');
+const cleanAJVErrorMessage = (message: string, path: Optional<string>, suggestion: Optional<string>) => {
+  const cleanMessage =
+    typeof path === 'string' ? message.trim().replace(new RegExp(`^${escapeRegExp(path)}:\\s*`), '') : message.trim();
+  return `${cleanMessage}${typeof suggestion === 'string' && suggestion.length > 0 ? `. ${suggestion}` : ''}`;
+};
 
 export const schema: IFunction<ISchemaOptions> = (targetVal, opts, paths) => {
   const results: IFunctionResult[] = [];
@@ -101,16 +107,16 @@ export const schema: IFunction<ISchemaOptions> = (targetVal, opts, paths) => {
       try {
         results.push(
           ...(betterAjvErrors(schemaObj, targetVal, validator.errors, { format: 'js' }) as IAJVOutputError[]).map(
-            ({ error, path: errorPath }) => ({
-              message: cleanAJVErrorMessage(error),
+            ({ suggestion, error, path: errorPath }) => ({
+              message: cleanAJVErrorMessage(error, errorPath, suggestion),
               path: [...path, ...(errorPath ? errorPath.replace(/^\//, '').split('/') : [])],
             }),
           ),
         );
       } catch {
         results.push(
           ...validator.errors.map(({ message, dataPath }) => ({
-            message: message ? cleanAJVErrorMessage(message) : '',
+            message: message ? cleanAJVErrorMessage(message, dataPath, void 0) : '',
             path: [
               ...path,
               ...dataPath

test-harness/scenarios/external-schemas-ruleset.scenario

@@ -11,7 +11,7 @@ lint {document} --ruleset ./test-harness/scenarios/rulesets/external-schemas-rul
 OpenAPI 3.x detected
 
 {document}
- 3:10  error  info-title        should be equal to one of the allowed values
- 4:16  error  info-description  should be equal to one of the allowed values
+ 3:10  error  info-title        should be equal to one of the allowed values: Stoplight, Stoplight.io, StoplightIO. Did you mean Stoplight?
+ 4:16  error  info-description  should be equal to one of the allowed values: foo, foo-bar, bar-foo
 
 ✖ 2 problems (2 errors, 0 warnings, 0 infos, 0 hints)

yarn.lock

@@ -103,7 +103,14 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.0.0"
 
-"@babel/runtime@^7.0.0", "@babel/runtime@^7.4.5":
+"@babel/runtime@^7.0.0":
+  version "7.6.0"
+  resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.6.0.tgz#4fc1d642a9fd0299754e8b5de62c631cf5568205"
+  integrity sha512-89eSBLJsxNxOERC0Op4vd+0Bqm6wRMqMbFtV3i0/fbaWw/mJ8Q3eBvgX0G4SyrOOLCtbu98HspF8o09MRT+KzQ==
+  dependencies:
+    regenerator-runtime "^0.13.2"
+
+"@babel/runtime@^7.4.5":
   version "7.5.5"
   resolved "https://registry.yarnpkg.com/@babel/runtime/-/runtime-7.5.5.tgz#74fba56d35efbeca444091c7850ccd494fd2f132"
   integrity sha512-28QvEGyQyNkB0/m2B4FU7IEZGK2NUrcMtT6BZEFALTguLk+AUT6ofsHtPk5QyjAdUkpMJ+/Em+quwz4HOt30AQ==
@@ -1096,10 +1103,10 @@ bcrypt-pbkdf@^1.0.0:
   dependencies:
     tweetnacl "^0.14.3"
 
-better-ajv-errors@0.6.6:
-  version "0.6.6"
-  resolved "https://registry.yarnpkg.com/better-ajv-errors/-/better-ajv-errors-0.6.6.tgz#967f3075ca43455021c4802c92761dfbf843188e"
-  integrity sha512-CD5Xb75GtFpwcPnGH60MFlqwhMt0uUhKEjCTaWNXa3btSEQ0dbokn4WbyuMy/ykpfa0miJ2fEU5iQWIVSXIXgw==
+better-ajv-errors@^0.6.7:
+  version "0.6.7"
+  resolved "https://registry.yarnpkg.com/better-ajv-errors/-/better-ajv-errors-0.6.7.tgz#b5344af1ce10f434fe02fc4390a5a9c811e470d1"
+  integrity sha512-PYgt/sCzR4aGpyNy5+ViSQ77ognMnWq7745zM+/flYO4/Yisdtp9wDQW2IKCyVYPUxQt3E/b5GBSwfhd1LPdlg==
   dependencies:
     "@babel/code-frame" "^7.0.0"
     "@babel/runtime" "^7.0.0"