fix: Disable ajv "strict mode" by default, as it generates a lot of noise on most OpenAPI documents.

Add `strictValidation` option to turn it back on.

fix #262

Author: jwalton

docs/Options.md

@@ -40,9 +40,9 @@ document in "/src/index.js", you could specify `controllers` as:
 import * as path from 'path';
 
 const options = {
-    controllers: path.resolve(__dirname, 'controllers'),
-    controllersPattern: "**/*.@(ts|js)"
-}
+  controllers: path.resolve(__dirname, 'controllers'),
+  controllersPattern: '**/*.@(ts|js)',
+};
 ```
 
 Then you can use [`x-exegesis-controller: Pets`](https://github.com/exegesis-js/exegesis/blob/master/docs/OAS3%20Specification%20Extensions.md)
@@ -67,11 +67,11 @@ for details.
 
 ## mimeTypeParsers
 
-An objet where keys are either mime types or mime type wildcards (e.g. 'text/*'),
+An objet where keys are either mime types or mime type wildcards (e.g. 'text/\*'),
 and values are parsers.
 
 This option is used to control how Exegesis parses message bodies and certain
-parameters. By default, parsers are provided for 'text/*' and
+parameters. By default, parsers are provided for 'text/\*' and
 'application/json'; however you can override either of these.
 
 OpenAPI 3.x defines special handling for 'application/x-www-form-urlencoded',
@@ -223,6 +223,10 @@ a discussion about the difference between these.
 
 This defaults to false, but in a future release it will default to true.
 
+## strictValidation
+
+If true, then this will put ajv into ["strict mode"](https://ajv.js.org/strict-mode.html).
+
 ## allErrors
 
 If set, then when encountering a validation error Exegesis will return

src/oas3/Schema/validators.ts

@@ -1,6 +1,6 @@
 import Ajv, { ValidateFunction } from 'ajv';
 import traveseSchema from 'json-schema-traverse';
-import { CustomFormats, IValidationError, ParameterLocation, ValidatorFunction } from '../../types';
+import { IValidationError, ParameterLocation, ValidatorFunction } from '../../types';
 import { resolveRef } from '../../utils/json-schema-resolve-ref';
 import * as jsonPaths from '../../utils/jsonPaths';
 import * as jsonSchema from '../../utils/jsonSchema';
@@ -48,12 +48,6 @@ function getParameterDescription(parameterLocation: ParameterLocation) {
     return description;
 }
 
-function addCustomFormats(ajv: Ajv, customFormats: CustomFormats) {
-    for (const key of Object.keys(customFormats)) {
-        ajv.addFormat(key, customFormats[key]);
-    }
-}
-
 function removeExamples(schema: any) {
     // ajv will print "schema id ignored" to stdout if an example contains a filed
     // named "id", so just axe all the examples.
@@ -211,9 +205,13 @@ function generateValidator(
         coerceTypes: allowTypeCoercion ? 'array' : false,
         removeAdditional: allowTypeCoercion ? 'failing' : false,
         allErrors: schemaContext.options.allErrors,
+        strict: schemaContext.options.strictValidation,
     });
 
-    addCustomFormats(ajv, customFormats);
+    for (const key of Object.keys(customFormats)) {
+        ajv.addFormat(key, customFormats[key]);
+    }
+
     const validate = ajv.compile(schema);
 
     return function (json: any) {

src/options.ts

@@ -36,6 +36,7 @@ export interface ExegesisCompiledOptions {
     validateDefaultResponses: boolean;
     allErrors: boolean;
     treatReturnedJsonAsPure: boolean;
+    strictValidation: boolean;
 }
 
 // See the OAS 3.0 specification for full details about supported formats:
@@ -132,5 +133,6 @@ export function compileOptions(options: ExegesisOptions = {}): ExegesisCompiledO
         validateDefaultResponses,
         allErrors: options.allErrors || false,
         treatReturnedJsonAsPure: options.treatReturnedJsonAsPure || false,
+        strictValidation: options.strictValidation ?? false,
     };
 }

src/types/options.ts

@@ -159,4 +159,9 @@ export interface ExegesisOptions {
      * will call `context.res.json(val)`.
      */
     treatReturnedJsonAsPure?: boolean;
+
+    /**
+     * If true, then this will put ajv into "strict mode" (see https://ajv.js.org/strict-mode.html).
+     */
+    strictValidation?: boolean;
 }