add types for 'parse-link-header' module (#18994)

* add types for 'parse-link-header' module

* updated return type

has possibility of returning null if input is falsy.

* Update parse-link-header-tests.ts

updated test to include null type.

types/parse-link-header/index.d.ts

@@ -0,0 +1,19 @@
+// Type definitions for parse-link-header 1.0
+// Project: https://github.com/thlorenz/parse-link-header
+// Definitions by: Nick Zelei <https://github.com/zelein>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+declare namespace parseLinkHeader {
+    interface Link {
+        url: string;
+        rel: string;
+        [queryParam: string]: string;
+    }
+
+    interface Links {
+        [rel: string]: Link;
+    }
+}
+
+declare function parseLinkHeader(linkHeader: string): parseLinkHeader.Links | null;
+export = parseLinkHeader;

types/parse-link-header/parse-link-header-tests.ts

@@ -0,0 +1,8 @@
+import * as parse from "parse-link-header";
+
+const linkHeader =
+    '<https://api.github.com/user/9287/repos?page=3&per_page=100>; rel="next", ' +
+    '<https://api.github.com/user/9287/repos?page=1&per_page=100>; rel="prev"; pet="cat", ' +
+    '<https://api.github.com/user/9287/repos?page=5&per_page=100>; rel="last"';
+
+const links: parse.Links | null = parse(linkHeader);

types/parse-link-header/tsconfig.json

@@ -0,0 +1,22 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "parse-link-header-tests.ts"
+    ]
+}

types/parse-link-header/tslint.json

@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }