Improved parameter parsing error handling

lib/middleware/index.js

@@ -3,6 +3,7 @@
 module.exports = Middleware;
 
 const _ = require("lodash");
+const ono = require("ono");
 const SwaggerParser = require("swagger-parser");
 const util = require("../helpers/util");
 const DataStore = require("../data-store");
@@ -46,7 +47,7 @@ function Middleware (sharedRouter) {
     let invalidArg = _.isFunction(openapi) || _.isDate(openapi) || _.isEmpty(openapi);
 
     if (invalidArg) {
-      throw new Error("Expected an OpenAPI 3.0 file or object");
+      throw ono("Expected an OpenAPI 3.0 file or object");
     }
 
     // Parse the OpenAPI definition

lib/middleware/parse-request/parse-parameter/index.js

@@ -2,6 +2,7 @@
 
 module.exports = parseParameter;
 
+const ono = require("ono");
 const ParseInfo = require("./parse-info");
 const parseMatrixParam = require("./parse-matrix-param");
 const parseLabelParam = require("./parse-label-param");
@@ -20,26 +21,50 @@ const parseDeepObjectParam = require("./parse-deep-object-param");
 function parseParameter (param, value) {
   let parseInfo = new ParseInfo({ param, value });
 
-  // Complex parameters have a `content` object instead of `style`, `schema`, `explode`, etc.
-  if (parseInfo.param.content) {
-    // return parseContentType(parseInfo);
+  try {
+    // Complex parameters have a `content` object instead of `style`, `schema`, `explode`, etc.
+    if (parseInfo.param.content) {
+      // return parseContentType(parseInfo);
+    }
+
+    // Simple parameters have a `style` and `schema`
+    switch (parseInfo.param.style) {
+      case "matrix":
+        return parseMatrixParam(parseInfo);
+      case "label":
+        return parseLabelParam(parseInfo);
+      case "form":
+        return parseFormParam(parseInfo);
+      case "simple":
+        return parseSimpleParam(parseInfo);
+      case "spaceDelimited":
+        return parseDelimitedParam(parseInfo, " ");
+      case "pipeDelimited":
+        return parseDelimitedParam(parseInfo, "|");
+      case "deepObject":
+        return parseDeepObjectParam(parseInfo);
+    }
+  }
+  catch (error) {
+    throw parseError(error, parseInfo);
   }
+}
 
-  // Simple parameters have a `style` and `schema`
-  switch (parseInfo.param.style) {
-    case "matrix":
-      return parseMatrixParam(parseInfo);
-    case "label":
-      return parseLabelParam(parseInfo);
-    case "form":
-      return parseFormParam(parseInfo);
-    case "simple":
-      return parseSimpleParam(parseInfo);
-    case "spaceDelimited":
-      return parseDelimitedParam(parseInfo, " ");
-    case "pipeDelimited":
-      return parseDelimitedParam(parseInfo, "|");
-    case "deepObject":
-      return parseDeepObjectParam(parseInfo);
+/**
+ * Creates a user-friendly error when a field cannot be parsed.
+ *
+ * @param   {Error}     error     - The original error
+ * @param   {ParseInfo} parseInfo - Information about the parameter value being parsed
+ * @returns {Error}
+ */
+function parseError (error, parseInfo) {
+  let { param, path } = parseInfo;
+
+  let message = `The "${param.name}" ${param.in} parameter is invalid.`;
+
+  if (path !== param.name) {
+    message += ` Error at ${path}.`;
   }
+
+  return ono.syntax(error, { status: 400 }, message);
 }