Allow label field to be optional.

This allows partial header parsing for secondary files (which are not allowed to have full headers due to `types-publisher`).

Author: leonard-thieu

src/parser/lax.ts

@@ -177,7 +177,7 @@ export let repo: P.Parser<model.Repository> = P.string('// Definitions: ')
 
 export let header: P.Parser<model.Header> = bomOpt
 	.then(P.seq(
-		label.skip(linebreak),
+		label.skip(linebreak).or(P.of(null)),
 		project.skip(linebreak),
 		authors.skip(linebreak),
 		repo.skip(linebreak)

test/fixtures/headers/angular~jqlite/fields.yml

@@ -0,0 +1,75 @@
+---
+  parsed:
+    label: null
+    project:
+      -
+       url:  "http://jquery.com"
+    authors:
+      -
+        name: Boris Yankov
+        url: "https://github.com/borisyankov"
+      -
+        name: Christian Hoffmeister
+        url: "https://github.com/choffmeister"
+      -
+        name: Steve Fenton
+        url: "https://github.com/Steve-Fenton"
+      -
+        name: Diullei Gomes
+        url: "https://github.com/Diullei"
+      -
+        name: Tass Iliopoulos
+        url: "https://github.com/tasoili"
+      -
+        name: Jason Swearingen
+        url: "https://github.com/jasons-novaleaf"
+      -
+        name: Sean Hill
+        url: "https://github.com/seanski"
+      -
+        name: Guus Goossens
+        url: "https://github.com/Guuz"
+      -
+        name: Kelly Summerlin
+        url: "https://github.com/ksummerlin"
+      -
+        name: Basarat Ali Syed
+        url: "https://github.com/basarat"
+      -
+        name: Nicholas Wolverson
+        url: "https://github.com/nwolverson"
+      -
+        name: Derek Cicerone
+        url: "https://github.com/derekcicerone"
+      -
+        name: Andrew Gaspar
+        url: "https://github.com/AndrewGaspar"
+      -
+        name: Seikichi Kondo
+        url: "https://github.com/seikichi"
+      -
+        name: Benjamin Jackman
+        url: "https://github.com/benjaminjackman"
+      -
+        name: Poul Sorensen
+        url: "https://github.com/s093294"
+      -
+        name: Josh Strobl
+        url: "https://github.com/JoshStrobl"
+      -
+        name: John Reilly
+        url: "https://github.com/johnnyreilly"
+      -
+        name: Dick van den Brink
+        url: "https://github.com/DickvdBrink"
+      -
+        name: Thomas Schulz
+        url: "https://github.com/King2500"
+      -
+        name: Leonard Thieu
+        url: "https://github.com/leonard-thieu"
+      -
+        name: Andre Wiggins
+        url: "https://github.com/andrewiggins"
+    repository:
+      url:  "https://github.com/DefinitelyTyped/DefinitelyTyped"