https://github.com/eeue56/baner
Flag parsing library in Typescript
https://github.com/eeue56/baner
Last synced: about 1 month ago
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Flag parsing library in Typescript
- Host: GitHub
- URL: https://github.com/eeue56/baner
- Owner: eeue56
- License: bsd-3-clause
- Created: 2021-06-03T20:49:44.000Z (almost 4 years ago)
- Default Branch: main
- Last Pushed: 2022-07-22T12:45:40.000Z (almost 3 years ago)
- Last Synced: 2025-03-02T15:16:46.123Z (2 months ago)
- Language: TypeScript
- Size: 108 KB
- Stars: 1
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# baner
Flag parsing library in Typescript
Part of the [Hiraeth](https://github.com/eeue56/hiraeth) collection.
# Installation
```bash
npm install --save @eeue56/baner
```
# Core functionality
The library is built on the ideas:
- A command line library might have multiple flags
- Every flag should have help text
- Arguments to the command line are either: strings, numbers, booleans, or lists of those
[API docs](docs/src/baner.md)
# Example
```typescript
import {
empty,
longFlag,
bothFlag,
number,
parse,
parser,
string,
help,
variableList,
oneOf,
allErrors,
allMissing,
} from "@eeue56/baner";
const helloParser = parser([
longFlag("name", "The name to say hi to", string()),
longFlag("age", "The age of the person", number()),
longFlag("pets", "Names of your pets", variableList(string())),
longFlag("type", "Type of owner", oneOf([ "human", "alien" ])),
bothFlag("h", "help", "This help text", empty()),
]);
function sayHi(
name: string,
age: number,
pets: string[],
type: "human" | "alien"
): void {
console.log(`Hi, ${name}! Congrats on being ${age} years old.`);
if (type === "alien") console.log("Welcome to earth!");
if (pets.length > 0) {
console.log(
`Wow, you had ${pets.length} pets. I bet ${pets.join(
", "
)} were good pets to have`
);
}
}
function showHelp(): void {
console.log("Provide a name via --name and age via --age");
console.log(help(helloParser));
}
const program = parse(helloParser, process.argv);
if (program.flags["h/help"].isPresent) {
showHelp();
} else {
const errors = allErrors(program);
const missing = allMissing(program, [ "h/help" ]);
if (errors.length > 0) {
console.log("Errors:");
console.log(errors.join("\n"));
} else if (missing.length > 0) {
console.log("Missing flags:");
console.log(missing.join("\n"));
} else {
sayHi(
(program.flags.name.arguments as Ok).value,
(program.flags.age.arguments as Ok).value as number,
(program.flags.pets.arguments as Ok).value as string[],
(program.flags.type.arguments as Ok).value as
| "human"
| "alien"
);
}
}
```
# Name
Baner means "flag" in Welsh. In English, you'd pronounce it as "ban-eh-eruh".