Issue 1:
I'm currently building type definitions for this library as I use it, so I'll eventually finish the whole thing.

However, if anyone has already written some, please contribute (or just link to a repo) to cut down on duplicate work. I can help with test coverage.

Issue 2:
I tried using the @types/webappsec-credential-management package and had problems.

I tried using the latest stable version of tsc. https://www.npmjs.com/package/typescript

[Mention]

Authors: @iainmcgin

I got lots of errors with typescript@2.2.1

ERROR in [at-loader] node_modules@types\webappsec-credential-management\index.d.ts:82:15

TS2300: Duplicate identifier 'URLSearchParams'.

ERROR in [at-loader] node_modules@types\whatwg-fetch\index.d.ts:11:13

TS2451: Cannot redeclare block-scoped variable 'fetch'.

ERROR in [at-loader] node_modules@types\whatwg-fetch\index.d.ts:13:14

TS2300: Duplicate identifier 'HeadersInit'.

ERROR in [at-loader] node_modules@types\whatwg-fetch\index.d.ts:14:15

TS2300: Duplicate identifier 'Headers'.

ERROR in [at-loader] node_modules@types\whatwg-fetch\index.d.ts:31:14

TS2300: Duplicate identifier 'BodyInit'.

ERROR in [at-loader] node_modules@types\whatwg-fetch\index.d.ts:43:14

TS2300: Duplicate identifier 'RequestInfo'.

ERROR in [at-loader] node_modules@types\whatwg-fetch\index.d.ts:44:15

TS2300: Duplicate identifier 'Request'.

ERROR in [at-loader] node_modules@types\whatwg-fetch\index.d.ts:64:11

TS2300: Duplicate identifier 'Request'.

ERROR in [at-loader] node_modules@types\whatwg-fetch\index.d.ts:88:15

TS2300: Duplicate identifier 'Response'.

ERROR in [at-loader] node_modules@types\whatwg-fetch\index.d.ts:107:11

TS2300: Duplicate identifier 'Response'.

ERROR in [at-loader] node_modules@types\whatwg-streams\index.d.ts:32:15

TS2300: Duplicate identifier 'ReadableStream'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:6945:11

TS2300: Duplicate identifier 'Headers'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:6954:13

TS2300: Duplicate identifier 'Headers'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:9321:11

TS2300: Duplicate identifier 'ReadableStream'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:9327:13

TS2300: Duplicate identifier 'ReadableStream'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:9343:11

TS2300: Duplicate identifier 'Request'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:9360:13

TS2300: Duplicate identifier 'Request'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:9365:11

TS2300: Duplicate identifier 'Response'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:9376:13

TS2300: Duplicate identifier 'Response'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:13858:11

TS2300: Duplicate identifier 'URLSearchParams'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:13885:13

TS2300: Duplicate identifier 'URLSearchParams'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:14893:18

TS2451: Cannot redeclare block-scoped variable 'fetch'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:14898:6

TS2300: Duplicate identifier 'BodyInit'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:14919:6

TS2300: Duplicate identifier 'HeadersInit'.

ERROR in [at-loader] node_modules\typescript\lib\lib.dom.d.ts:14929:6

TS2300: Duplicate identifier 'RequestInfo'.