fix(man-page): keep the last environment variable when its section ends the input

.changeset/man-page-last-env-var.md

@@ -0,0 +1,5 @@
+---
+'@node-core/doc-kit': patch
+---
+
+The man page no longer drops the last environment variable when that section ends the input.

packages/node/src/man-page/__tests__/generate.test.mjs

@@ -0,0 +1,56 @@
+import assert from 'node:assert/strict';
+import { describe, it } from 'node:test';
+
+import { setConfig } from '@doc-kit/core/utils/configuration/index.mjs';
+import { u } from 'unist-builder';
+
+import { generate } from '../generate.mjs';
+
+const config = await setConfig({ target: ['man-page'] });
+config['man-page'].output = undefined;
+
+const entry = (depth, slug, text, description = '') => {
+  const heading = u('heading', { depth }, [u('text', text)]);
+
+  return {
+    heading: { depth, data: { slug, text } },
+    content: u('root', [heading, u('paragraph', [u('text', description)])]),
+  };
+};
+
+describe('man-page generate', () => {
+  it('keeps the last environment variable when the section ends the input', async () => {
+    const input = [
+      entry(1, 'command-line-api', 'Command-line API'),
+      entry(2, 'environment-variables', 'Environment variables', 'Intro.'),
+      entry(2, 'options', 'Options'),
+      entry(3, '--foo', '`--foo`', 'Foo option.'),
+      entry(2, 'environment-variables-1', 'Environment variables'),
+      entry(3, 'node_onevalue', '`NODE_ONE=value`', 'First var.'),
+      entry(3, 'node_twovalue', '`NODE_TWO=value`', 'Second var.'),
+      entry(3, 'node_threevalue', '`NODE_THREE=value`', 'Third var.'),
+    ];
+
+    const output = await generate(input);
+
+    assert.match(output, /\.It Ev NODE_ONE Ar value\nFirst var\./);
+    assert.match(output, /\.It Ev NODE_TWO Ar value\nSecond var\./);
+    assert.match(output, /\.It Ev NODE_THREE Ar value\nThird var\./);
+  });
+
+  it('stops the environment variables at the next section', async () => {
+    const input = [
+      entry(2, 'options', 'Options'),
+      entry(3, '--foo', '`--foo`', 'Foo option.'),
+      entry(2, 'environment-variables-1', 'Environment variables'),
+      entry(3, 'node_onevalue', '`NODE_ONE=value`', 'First var.'),
+      entry(2, 'useful-v8-options', 'Useful V8 options'),
+      entry(3, '--max-old-space-size', '`--max-old-space-size=SIZE`', 'Heap.'),
+    ];
+
+    const output = await generate(input);
+
+    assert.match(output, /\.It Ev NODE_ONE Ar value\nFirst var\./);
+    assert.doesNotMatch(output, /max-old-space-size/);
+  });
+});

packages/node/src/man-page/generate.mjs

@@ -43,11 +43,15 @@ export async function generate(input) {
     ({ heading }) => heading.data.slug === config.envVarsHeaderSlug
   );
 
-  // The first header that is <3 in depth after environmentStart
-  const environmentEnd = input.findIndex(
+  // The first header that is <3 in depth after environmentStart,
+  // or the end of the input when the section is the last one
+  const nextSectionStart = input.findIndex(
     ({ heading }, index) => heading.depth < 3 && index > environmentStart
   );
 
+  const environmentEnd =
+    nextSectionStart === -1 ? input.length : nextSectionStart;
+
   const output = {
     // Extract the CLI options.
     options: extractMandoc(