docs: fix the README

README.md

@@ -139,7 +139,8 @@ try {
   (error as InvalidAddressError).chain; // "bitcoin"
 }
 
-identify("0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984").matches.length; // 13
+const { matches } = identify("0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984");
+matches.every((chain) => chain.type === "evm"); // true, and that's as far as a 0x address narrows
 create("bitcoin").decimals; // 8
 metadata("decred").symbol; // "DCR", read from a table, no Decred class behind it
 ```

test/run-cli.ts

@@ -0,0 +1,30 @@
+import { createCli } from "@agntn/tools/cli";
+import { vi } from "vite-plus/test";
+import { cliOptions } from "../src/cli-commands.ts";
+
+/** What one command line wrote and how it exited. */
+export interface Run {
+  readonly code: typeof process.exitCode;
+  readonly stderr: string;
+  readonly stdout: string;
+}
+
+/**
+ * Runs one command line through the CLI the bin builds and collects both streams.
+ *
+ * @param args - Words after `chains`.
+ * @returns {Promise<Run>} The exit code and what reached stdout and stderr, trailing newline cut.
+ */
+export async function run(...args: readonly string[]): Promise<Run> {
+  const written = { stdout: "", stderr: "" };
+  for (const stream of ["stdout", "stderr"] as const) {
+    vi.spyOn(process[stream], "write").mockImplementation((chunk: unknown) => {
+      written[stream] += String(chunk);
+      return true;
+    });
+  }
+  await createCli(cliOptions).run(args);
+  const code = process.exitCode;
+  vi.restoreAllMocks();
+  return { code, stdout: written.stdout.trimEnd(), stderr: written.stderr.trimEnd() };
+}

test/unit/cli.test.ts

@@ -1,10 +1,9 @@
 import { spawn } from "node:child_process";
 import { once } from "node:events";
 import { resolve as resolvePath } from "node:path";
-import { createCli } from "@agntn/tools/cli";
 import { afterEach, describe, expect, it, vi } from "vite-plus/test";
-import { cliOptions } from "../../src/cli-commands.ts";
 import { Chain, register, type ChainKey } from "../../src/index.ts";
+import { run } from "../run-cli.ts";
 
 /** No built-in chain lacks a txid check any more, so the CLI message needs a registered stand-in. */
 class Unvalidated extends Chain {
@@ -21,33 +20,6 @@ const ESCAPE = String.fromCodePoint(27);
 const CSI = String.fromCodePoint(155);
 const CONTROL = /[\p{Cc}\p{Cf}\p{Zl}\p{Zp}]/u;
 
-/** What one command line wrote and how it exited. */
-interface Run {
-  readonly code: typeof process.exitCode;
-  readonly stderr: string;
-  readonly stdout: string;
-}
-
-/**
- * Runs one command line through the CLI the bin builds and collects both streams.
- *
- * @param args - Words after `chains`.
- * @returns {Promise<Run>} The exit code and what reached stdout and stderr, trailing newline cut.
- */
-async function run(...args: readonly string[]): Promise<Run> {
-  const written = { stdout: "", stderr: "" };
-  for (const stream of ["stdout", "stderr"] as const) {
-    vi.spyOn(process[stream], "write").mockImplementation((chunk: unknown) => {
-      written[stream] += String(chunk);
-      return true;
-    });
-  }
-  await createCli(cliOptions).run(args);
-  const code = process.exitCode;
-  vi.restoreAllMocks();
-  return { code, stdout: written.stdout.trimEnd(), stderr: written.stderr.trimEnd() };
-}
-
 afterEach(() => {
   vi.restoreAllMocks();
   process.exitCode = undefined;

test/unit/readme.test.ts

@@ -0,0 +1,33 @@
+import { readFileSync } from "node:fs";
+import { afterEach, describe, expect, it } from "vite-plus/test";
+import { run } from "../run-cli.ts";
+
+/** One command the README runs and the output it prints right under it. */
+const TRANSCRIPT = /```bash\n(?:npx @agntn\/chains|chains) ([^\n]+)\n```\n\n```\n(.+?)\n```/gsu;
+
+const readme = readFileSync(new URL("../../README.md", import.meta.url), "utf8");
+
+const transcripts = [...readme.matchAll(TRANSCRIPT)].map(
+  ([, command = "", printed = ""]) => [command, printed] as const,
+);
+
+afterEach(() => {
+  process.exitCode = undefined;
+});
+
+describe("README transcripts", () => {
+  it("finds every command the README answers", () => {
+    expect(transcripts.map(([command]) => command)).toEqual([
+      "info matic",
+      "identify 0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984",
+      "identify bc1qjvm9jkrjw9uvsn8905dwa6eau0guyc9laau03a",
+      "validate btc 1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN3",
+    ]);
+  });
+
+  it.each(transcripts)("chains %s prints what the README shows", async (command, printed) => {
+    const { stderr, stdout } = await run(...command.split(" "));
+
+    expect(stdout || stderr).toBe(printed);
+  });
+});