Adds query string serialization optimization

Respects the `explode` attribute. When defined the actual serialization includes a duplication of the parameter. Otherwise arrays will be serialized in a comma-separated way.

Signed-off-by: André König <[email protected]>

Author: akoenig

packages/openapi-to-graphql/src/oas_3_tools.ts

@@ -388,7 +388,19 @@ export function instantiatePathAndGetQuery(
 
           // Query parameters
           case 'query':
-            query[param.name] = args[sanitizedParamName]
+            //
+            // Spec-compliant query string serialization:
+            // http://spec.openapis.org/oas/v3.0.3#style-examples
+            //
+            // Whenever the query string value is an array, we check if it
+            // should be `exploded`. In this case, we don't serialize anything.
+            // Otherwise, the array will be joined in comma-separated fashion.
+            //
+            //
+            const arg = args[sanitizedParamName]
+            const shouldBeCommaSeparated = Array.isArray(arg) && !param.explode
+
+            query[param.name] = shouldBeCommaSeparated ? arg.join(",") : arg
             break
 
           // Header parameters

packages/openapi-to-graphql/src/resolver_builder.ts

@@ -339,7 +339,14 @@ export function getResolver({
     )
 
     return new Promise((resolve, reject) => {
-      NodeRequest(options, (err, response, body) => {
+      NodeRequest({...options,
+        //
+        // Use `native` querystring library to avoid `foo[0]=bar&foo[1]=baz`
+        // which is not spec compliant. See https://github.com/request/request#requestoptions-callback
+        // for further information.
+        //
+        useQuerystring: true,
+      }, (err, response, body) => {
         if (err) {
           httpLog(err)
           reject(err)

packages/openapi-to-graphql/test/example_api2.test.ts

@@ -75,6 +75,9 @@ test('Querying the two operations', () => {
     user {
       name
     }
+    getRobots(types: ["Droid", "Bot"]) {
+      name
+    }
   }`
   return graphql(createdSchema, query).then(result => {
     expect(result).toEqual({
@@ -84,6 +87,9 @@ test('Querying the two operations', () => {
         },
         user: {
           name: 'William B Ropp'
+        },
+        getRobots: {
+          name: "Nkiru Gwendoline"
         }
       }
     })

packages/openapi-to-graphql/test/example_api2_server.js

@@ -31,6 +31,13 @@ function startServer(PORT) {
     })
   })
 
+  app.get('/api/robots', (req, res) => {
+    console.log(req.method, req.path)
+    res.send({
+      name: "Nkiru Gwendoline"
+    })
+  })
+
   return new Promise(resolve => {
     server = app.listen(PORT, () => {
       console.log(`Example API accessible on port ${PORT}`)

packages/openapi-to-graphql/test/fixtures/example_oas2.json

@@ -73,6 +73,36 @@
           }
         }
       }
+    },
+    "/robots": {
+      "get": {
+        "description": "",
+        "parameters": [
+          {
+            "in": "query",
+            "name": "types",
+            "required": true,
+            "schema": {
+              "type": "array",
+              "items": {
+                "type": "string"
+              }
+            }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/robot"
+                }
+              }
+            }
+          }
+        }
+      }
     }
   },
   "components": {
@@ -86,6 +116,16 @@
             "description": "The legal name of a user"
           }
         }
+      },
+      "robot": {
+        "type": "object",
+        "description": "A robot represents a not so natural person",
+        "properties": {
+          "name": {
+            "type": "string",
+            "description": "The legal name of a robot"
+          }
+        }
       }
     }
   },