types/argparse: Minimal support for custom actions

types/argparse/argparse-tests.ts

@@ -1,6 +1,12 @@
 // near copy of each of the tests from https://github.com/nodeca/argparse/tree/master/examples
 
-import { ArgumentParser, RawDescriptionHelpFormatter } from 'argparse';
+import {
+    ArgumentParser,
+    RawDescriptionHelpFormatter,
+    Action,
+    ActionConstructorOptions,
+    Namespace,
+} from 'argparse';
 let args: any;
 
 const simpleExample = new ArgumentParser({
@@ -276,3 +282,26 @@ group.addArgument(['--bar'], {
     help: 'bar help'
 });
 formatterExample.printHelp();
+
+class CustomAction1 extends Action {
+    constructor(options: ActionConstructorOptions) {
+        super(options);
+    }
+    call(parser: ArgumentParser, namespace: Namespace, values: string | string[], optionString: string | null) {
+        console.log('custom action 1');
+    }
+}
+
+class CustomAction2 extends Action {
+    call(parser: ArgumentParser, namespace: Namespace, values: string | string[], optionString: string | null) {
+        console.log('custom action 2');
+    }
+}
+
+const customActionExample = new ArgumentParser({ addHelp: false });
+customActionExample.addArgument('--abc', {
+    action: CustomAction1,
+});
+customActionExample.addArgument('--def', {
+    action: CustomAction2,
+});

types/argparse/index.d.ts

@@ -3,6 +3,7 @@
 // Definitions by: Andrew Schurman <https://github.com/arcticwaters>
 //                 Tomasz Łaziuk <https://github.com/tlaziuk>
 //                 Sebastian Silbermann <https://github.com/eps1lon>
+//                 Kannan Goundan <https://github.com/cakoose>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.2
 
@@ -79,13 +80,24 @@ export interface ArgumentGroupOptions {
     description?: string;
 }
 
+export abstract class Action {
+    protected dest: string;
+    constructor(options: ActionConstructorOptions);
+    abstract call(parser: ArgumentParser, namespace: Namespace, values: string | string[], optionString: string | null): void;
+}
+
+// Passed to the Action constructor.  Subclasses are just expected to relay this to
+// the super() constructor, so using an "opaque type" pattern is probably fine.
+// Someone may want to fill this out in the future.
+export type ActionConstructorOptions = number & {_: 'ActionConstructorOptions'};
+
 export class HelpFormatter { }
 export class ArgumentDefaultsHelpFormatter { }
 export class RawDescriptionHelpFormatter { }
 export class RawTextHelpFormatter { }
 
 export interface ArgumentOptions {
-    action?: string;
+    action?: string | { new(options: ActionConstructorOptions): Action };
     optionStrings?: string[];
     dest?: string;
     nargs?: string | number;

types/argparse/tsconfig.json

@@ -21,4 +21,4 @@
         "index.d.ts",
         "argparse-tests.ts"
     ]
-}
+}