From 19c6f4918e3b7d89cacc4212e27a789db0521ec9 Mon Sep 17 00:00:00 2001
From: Carmine DiMascio <cdimascio@gmail.com>
Date: Fri, 27 Nov 2020 21:25:24 -0500
Subject: [PATCH] fix: parameter style handling #473 (#474)

---
 src/middlewares/parsers/util.ts         | 34 ++++++++++++++-
 test/query.serialization.ts             | 46 ++++++++++++++++++++
 test/resources/query.serialization.yaml | 58 +++++++++++++++++++++++++
 3 files changed, 137 insertions(+), 1 deletion(-)
 create mode 100644 test/query.serialization.ts
 create mode 100644 test/resources/query.serialization.yaml

diff --git a/src/middlewares/parsers/util.ts b/src/middlewares/parsers/util.ts
index e3864aca..f7031d93 100644
--- a/src/middlewares/parsers/util.ts
+++ b/src/middlewares/parsers/util.ts
@@ -31,7 +31,7 @@ export function normalizeParameter(
   } else if (parameter?.schema?.['$ref']) {
     schema = dereferenceSchema(ajv, parameter.schema['$ref']);
   } else {
-    schema = parameter.schema 
+    schema = parameter.schema;
   }
   if (!schema && parameter.content) {
     const contentType = Object.keys(parameter.content)[0];
@@ -41,11 +41,43 @@ export function normalizeParameter(
     schema = parameter;
   }
 
+  applyParameterStyle(parameter);
+  applyParameterExplode(parameter);
+
   const name =
     parameter.in === 'header' ? parameter.name.toLowerCase() : parameter.name;
+
   return { name, schema };
 }
 
+function applyParameterStyle(param: OpenAPIV3.ParameterObject) {
+  if (!param.style) {
+    if (param.in === 'path') {
+      param.style = 'simple';
+    } else if (param.in === 'query') {
+      param.style = 'form';
+    } else if (param.style === 'header') {
+      param.style = 'simple';
+    } else if (param.style === 'cookie') {
+      param.style = 'form';
+    }
+  }
+}
+
+function applyParameterExplode(param: OpenAPIV3.ParameterObject) {
+  if (param.explode == null) {
+    if (param.in === 'path') {
+      param.explode = false;
+    } else if (param.in === 'query') {
+      param.explode = true;
+    } else if (param.style === 'header') {
+      param.explode = false;
+    } else if (param.style === 'cookie') {
+      param.explode = true;
+    }
+  }
+}
+
 export function dereferenceSchema(ajv: Ajv, ref: string) {
   // TODO cache schemas - so that we don't recurse every time
   const derefSchema = ajv.getSchema(ref);
diff --git a/test/query.serialization.ts b/test/query.serialization.ts
new file mode 100644
index 00000000..78435907
--- /dev/null
+++ b/test/query.serialization.ts
@@ -0,0 +1,46 @@
+import * as path from 'path';
+import * as express from 'express';
+import { expect } from 'chai';
+import * as request from 'supertest';
+import { createApp } from './common/app';
+import * as packageJson from '../package.json';
+import { log } from 'console';
+
+describe.only('styles', () => {
+  let app = null;
+  before(async () => {
+    const apiSpec = path.join('test', 'resources', 'query.serialization.yaml');
+    app = await createApp({ apiSpec }, 3005, (app) =>
+      app.use(
+        `/`,
+        express
+          .Router()
+          .get('/api/q_form_explode', (req, res) => res.json({ query: req.query }))
+          .get('/api/q_form_nexplode', (req, res) => res.json({ query: req.query })),
+      ),
+    );
+  });
+
+  after(async () => {
+    app.server.close();
+  });
+
+  it('should handle querey param (default) style=form, explode=true', async () =>
+    request(app)
+      .get('/api/q_form_explode?state=on&state=off')
+      .expect(200)
+      .then((r) => {
+        expect(r.body.query.state).is.an('array').of.length(2);
+      }));
+
+  it.only('should handle query param with style=form, explode=false', async () =>
+    request(app)
+      .get('/api/q_form_nexplode')
+      .query({
+        state: 'on,off',
+      })
+      .expect(200)
+      .then((r) => {
+        expect(r.body.query.state).is.an('array').of.length(2);
+      }));
+});
diff --git a/test/resources/query.serialization.yaml b/test/resources/query.serialization.yaml
new file mode 100644
index 00000000..5ffb5d24
--- /dev/null
+++ b/test/resources/query.serialization.yaml
@@ -0,0 +1,58 @@
+openapi: '3.0.3'
+info:
+  title: Dummy
+  version: '0.1.0'
+
+paths:
+  /api/q_form_explode:
+    get:
+      parameters: 
+        - description: Description
+          schema:
+            title: State
+            type: array
+            items:
+              $ref: '#/components/schemas/Foo'
+            description: A description
+          name: state
+          in: query
+      responses:
+        200:
+          description: OK
+          content:
+            'application/json; charset=utf-8':
+              schema:
+                type: object
+
+  /api/q_form_nexplode:
+    get:
+      parameters: 
+        - description: Description
+          required: false
+          explode: false
+          schema:
+            title: State
+            type: array
+            items:
+              $ref: '#/components/schemas/Foo'
+            description: A description
+          name: state
+          in: query        
+      responses:
+        200:
+          description: OK
+          content:
+            'application/json; charset=utf-8':
+              schema:
+                type: object
+                
+                
+components:
+  schemas:
+    Foo:
+      type: string
+      enum:
+        - on
+        - off
+      
+      
\ No newline at end of file