function renderGuide
renderGuide(guide: Guide): string

Renders a guidance screen.

Blocks are separated by a blank line and the result carries no trailing newline, so the caller can hand it straight to console.error or console.log. The function is pure — the same Guide always renders the same string — which is what lets the disclosure levels, the error paths and --help be tested without a process.

Examples

The three blocks of an incomplete invocation

import { assertEquals } from "@std/assert";
import { renderGuide } from "./guide.ts";

const text = renderGuide({
  next: { word: "<command>", meaning: "what to do with the bytes" },
  options: {
    heading: "COMMANDS",
    items: [
      { name: "decode", summary: "binary on stdin to JSON5 on stdout" },
      { name: "encode", summary: "JSON5 on stdin to binary on stdout" },
    ],
  },
  try: ["binstruct arp decode < arp.bin > arp.json5"],
});

assertEquals(text.split("\n\n"), [
  "NEXT  <command>\n  what to do with the bytes",
  "COMMANDS\n  decode  binary on stdin to JSON5 on stdout\n" +
  "  encode  JSON5 on stdin to binary on stdout",
  "TRY\n  binstruct arp decode < arp.bin > arp.json5",
]);

Bare names are flowed into columns, and an empty list explains itself

import { assertEquals, assertStringIncludes } from "@std/assert";
import { renderGuide } from "./guide.ts";

const flowed = renderGuide({
  next: { word: "<package>", meaning: "the format package" },
  options: { heading: "PACKAGES", items: [{ name: "arp" }, { name: "png" }] },
});

assertStringIncludes(flowed, "\n  arp  png");

const empty = renderGuide({
  header: "package: jsr:@binstruct/pcap",
  next: { word: "<coder>", meaning: "the coder to run" },
  options: { heading: "CODERS", items: [], empty: "discovery is unavailable" },
});

assertEquals(empty.split("\n")[0], "package: jsr:@binstruct/pcap");
assertStringIncludes(empty, "\n  discovery is unavailable");

Parameters

guide: Guide

The screen to render

Return Type

string

The rendered text, without a trailing newline

Usage

import { renderGuide } from "mod.ts";