@xterm/addon-fit 0.10.0: FitAddon

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify @xterm/addon-fit.FitAddon in pkg:npm/%40xterm/addon-fit@0.10.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/%40xterm/addon-fit@0.10.0
Demonstrate these symbols/APIs:
  - @xterm/addon-fit.FitAddon

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:a9f0c827dc451e1eb5b63f7194a5a33d4d3c6df1431b65f77f72723c5c42df27","contract":["new FitAddon() creates an instance with activate, dispose, fit, and proposeDimensions methods","fitAddon.proposeDimensions() returns undefined when terminal is not attached or lacks DOM element","fitAddon.proposeDimensions() calculates terminal cols and rows based on container dimensions and cell geometry","fitAddon.fit() triggers terminal resize to proposed dimensions and clears renderer cache","fitAddon.dispose() cleanly completes addon lifecycle"],"goal":"verify @xterm/addon-fit.FitAddon in pkg:npm/%40xterm/addon-fit@0.10.0","kind":"HOW","packages":["pkg:npm/%40xterm/addon-fit@0.10.0"],"schemaVersion":1,"symbols":["@xterm/addon-fit.FitAddon"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/%40xterm/addon-fit@0.10.0"],"schemaVersion":1,"subject":"pkg:npm/%40xterm/addon-fit@0.10.0","symbols":["@xterm/addon-fit.FitAddon"],"verifierAdapter":"node-typescript@1"}

{
  "name": "sample-addon-fit",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-addon-fit",
      "version": "1.0.0",
      "dependencies": {
        "@xterm/addon-fit": "0.10.0"
      }
    },
    "node_modules/@xterm/addon-fit": {
      "version": "0.10.0",
      "resolved": "https://registry.npmjs.org/@xterm/addon-fit/-/addon-fit-0.10.0.tgz",
      "integrity": "sha512-UFYkDm4HUahf2lnEyHvio51TNGiLK66mqP2JoATy7hRZeXaGMRDr00JiSF7m63vR5WKATF605yEggJKsw0JpMQ==",
      "license": "MIT",
      "peerDependencies": {
        "@xterm/xterm": "^5.0.0"
      }
    },
    "node_modules/@xterm/xterm": {
      "version": "5.5.0",
      "resolved": "https://registry.npmjs.org/@xterm/xterm/-/xterm-5.5.0.tgz",
      "integrity": "sha512-hqJHYaQb5OptNunnyAnkHyM8aCjZ1MEIDTQu1iIbbTD/xops91NB5yq1ZK/dC2JDbVWtF23zUtl9JE2NqwT87A==",
      "license": "MIT",
      "peer": true
    }
  }
}

{
  "name": "sample-addon-fit",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "dependencies": {
    "@xterm/addon-fit": "0.10.0"
  }
}

{
  "schemaVersion": 1,
  "goal": "verify @xterm/addon-fit.FitAddon in pkg:npm/%40xterm/addon-fit@0.10.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/%40xterm/addon-fit@0.10.0"
  ],
  "symbols": [
    "@xterm/addon-fit.FitAddon"
  ]
}

import assert from 'node:assert/strict';

// Node.js compatibility: @xterm/addon-fit expects global `self` and `window`
globalThis.self = globalThis;

// Dynamic import ensures globalThis.self is defined before evaluating addon-fit module
const { FitAddon } = await import('@xterm/addon-fit');

// 1. Instantiation and API surface
const fitAddon = new FitAddon();
assert.equal(typeof fitAddon.activate, 'function');
assert.equal(typeof fitAddon.dispose, 'function');
assert.equal(typeof fitAddon.fit, 'function');
assert.equal(typeof fitAddon.proposeDimensions, 'function');

// 2. Propose dimensions without attached terminal
assert.equal(fitAddon.proposeDimensions(), undefined);

// 3. Propose dimensions when terminal lacks DOM element
const unattachedTerminal = {
  rows: 24,
  cols: 80,
  options: { scrollback: 1000 },
  _core: {}
};
fitAddon.activate(unattachedTerminal);
assert.equal(fitAddon.proposeDimensions(), undefined);

// 4. Fitting with mock DOM environment and terminal render dimensions
const parentElement = {};
const terminalElement = { parentElement };
let resizedCols = 0;
let resizedRows = 0;
let cleared = false;

const mockTerminal = {
  element: terminalElement,
  rows: 24,
  cols: 80,
  options: { scrollback: 1000 },
  _core: {
    _renderService: {
      dimensions: {
        css: {
          cell: { width: 9, height: 17 }
        }
      },
      clear: () => {
        cleared = true;
      }
    },
    viewport: { scrollBarWidth: 15 }
  },
  resize: (cols, rows) => {
    resizedCols = cols;
    resizedRows = rows;
    mockTerminal.cols = cols;
    mockTerminal.rows = rows;
  }
};

globalThis.window = {
  getComputedStyle: (el) => {
    if (el === parentElement) {
      return {
        getPropertyValue: (prop) => {
          if (prop === 'height') return '680px';
          if (prop === 'width') return '915px';
          return '0px';
        }
      };
    }
    if (el === terminalElement) {
      return {
        getPropertyValue: (prop) => '0px'
      };
    }
    return { getPropertyValue: () => '0px' };
  }
};

fitAddon.activate(mockTerminal);

// Propose dimensions calculation:
// availableWidth = 915 - 0 (padding) - 15 (scrollbar) = 900 -> cols = 900 / 9 = 100
// availableHeight = 680 - 0 (padding) = 680 -> rows = 680 / 17 = 40
const dimensions = fitAddon.proposeDimensions();
assert.deepEqual(dimensions, { cols: 100, rows: 40 });

// Trigger terminal fit and verify resize + render clear
fitAddon.fit();
assert.equal(resizedCols, 100);
assert.equal(resizedRows, 40);
assert.equal(cleared, true);

// 5. Dispose cleanup
fitAddon.dispose();