c-headers: do not list PRI as a valid HTTP method

PRI gets special treatment (parse preamble and error) and even though it
is parsed and allowed after `HTTP/1.x` - it is not technically a method
that could appear in the request parsed with llhttp. Remove the method
from the list of HTTP methods in C headers to prevent confusion and
breakage of `body-parser`.

PR-URL: nodejs/llhttp#105
Reviewed-By: Beth Griggs <bgriggs@redhat.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

Author: alex-dev-2012

src/llhttp/c-headers.ts

@@ -18,7 +18,9 @@ export class CHeaders {
 
     const errorMap = enumToMap(constants.ERROR);
     const methodMap = enumToMap(constants.METHODS);
-    const httpMethodMap = enumToMap(constants.METHODS, constants.METHODS_HTTP);
+    const httpMethodMap = enumToMap(constants.METHODS, constants.METHODS_HTTP, [
+      constants.METHODS.PRI,
+    ]);
     const rtspMethodMap = enumToMap(constants.METHODS, constants.METHODS_RTSP);
 
     res += this.buildEnum('llhttp_errno', 'HPE', errorMap);

src/llhttp/utils.ts

@@ -2,7 +2,11 @@ export interface IEnumMap {
   [key: string]: number;
 }
 
-export function enumToMap(obj: any, filter?: ReadonlyArray<number>): IEnumMap {
+export function enumToMap(
+  obj: any,
+  filter?: ReadonlyArray<number>,
+  exceptions?: ReadonlyArray<number>,
+): IEnumMap {
   const res: IEnumMap = {};
 
   Object.keys(obj).forEach((key) => {
@@ -13,6 +17,9 @@ export function enumToMap(obj: any, filter?: ReadonlyArray<number>): IEnumMap {
     if (filter && !filter.includes(value)) {
       return;
     }
+    if (exceptions && exceptions.includes(value)) {
+      return;
+    }
     res[key] = value;
   });