Clerc Official DocsInterceptors
An interceptor is a function that runs before or after calling the command handler, like middleware in koa.
Usage
Interceptors are added to the cli using the interceptor method:
ts
import { Clerc } from "clerc";
const cli = Clerc.create()
.scriptName("foo-cli")
.description("A simple cli")
.version("1.0.0")
.command("foo", "A foo command")
.interceptor((context, next) => {
console.log("Before foo");
// You can inject something into the context, or modify the context
context.foo = "bar";
next(); // Call next to continue
})
.parse();Order
The interceptor method accepts either a function or an object:
ts
import { Clerc } from "clerc";
const cli = Clerc.create()
.scriptName("foo-cli")
.description("A simple cli")
.version("1.0.0")
.command("foo", "A foo command")
.interceptor({
enforce: "normal", // default, or 'pre', 'post'
fn: (context, next) => {
console.log("Before foo");
// You can inject something into the context, or modify the context
context.foo = "bar";
next(); // Call next to continue
},
})
.parse();So the order of execution is:
- Pre interceptors
- Normal interceptors
- Post interceptors
Call after command handler
You can do something after the command handler is called by doing things after calling next():
ts
import { Clerc } from "clerc";
const cli = Clerc.create()
.scriptName("foo-cli")
.description("A simple cli")
.version("1.0.0")
.command("foo", "A foo command")
.interceptor((context, next) => {
console.log("Before foo");
// You can inject something into the context, or modify the context
context.foo = "bar";
next(); // Call next to continue
console.log("After foo");
})
.on("foo", (context) => {
console.log("It works!");
})
.parse();
// The output is:
// Before foo
// It works!
// After foo