Type Alias FunctionOpenMessage<Args>

How the opening box message is built for trace.info().

Templates render against the traced name, and parent. prefixes it with the class a traced method belongs to, or the file a traced plain function is written in. For a method calculate(price: number, quantity: number) of class Checkout, called as calculate(19.95, 3):

'fn' — calculate()
'parent.fn' — Checkout.calculate() (also the default when openMessage is omitted)
'fn(types)' — calculate(number, number) (typeof each argument)
'fn(args)' — calculate(19.95, 3) (arguments stringified into the message)
'parent.fn(types)' — Checkout.calculate(number, number)
'parent.fn(args)' — Checkout.calculate(19.95, 3)

Every template is colored in the props printer's palette: the text between the parentheses the way a string is printed, the function name and its parent the way a function and a class are. The parentheses, the separators and the done suffix stay in the color of the message around them.

A callback receives a TraceOpenMessageContext and must return the message string. Args is inferred from the target a trace.info() marker names; pass it explicitly on trace.info<Args, Result>(options).

Type Parameters

Args extends readonly unknown[] = readonly unknown[]

Example

import { trace } from 'loxer/trace';

trace.info(calculate, { openMessage: 'fn(args)' });

import { trace } from 'loxer/trace';

trace.info(calculate, {
  openMessage: ({ args: [price, quantity], parentFn }) => parentFn(`${price} × ${quantity}`),
});

import { trace } from 'loxer/trace';

function calculate(price: number, quantity: number) {
  trace.info<[number, number]>({
    openMessage: ({ args: [p, q], parentFn }) => parentFn(`${p} × ${q}`),
  });
}

Type Alias FunctionOpenMessage<Args>

Type Parameters

Example

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