Registry / type-stubs / typescript-coverage-report

typescript-coverage-report

library1.1.1jsnpmunverified

typescript-coverage-report is a Node.js command-line tool designed to generate comprehensive type coverage reports for TypeScript projects. It visually highlights areas in the codebase that lack strong typing, helping developers track progress in TypeScript adoption or maintain strict type discipline. Currently at version 1.1.1, the package seems to follow an ad-hoc release cadence, with previous minor versions addressing specific TypeScript compatibility issues and feature enhancements. Its key differentiator is being strongly inspired by and filling a similar niche to `flow-coverage-report` in the Flow ecosystem, leveraging data from the `type-coverage` package to analyze `any` usage.

type-stubs

npm install typescript-coverage-report

github ↗package ↗

INSTALL

IMPORT

SIG · TYPESCRIPT-COVERAG

typescript-coverage-report

type-stubsjavascriptv1.1.1

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

CLI Execution

✓ npx typescript-coverage-report

✗ import { generateReport } from 'typescript-coverage-report'

This package is primarily a command-line interface (CLI) tool. It is not designed for direct programmatic import of its functions. The `npx` command executes the locally installed binary.

CLI Execution (via package.json script)

✓ "scripts": { "ts-coverage": "typescript-coverage-report" }` then `npm run ts-coverage`

✗ Attempting to run `typescript-coverage-report` directly if not globally installed or in PATH.

For local installations, adding a script to `package.json` is the recommended way to invoke the CLI, making it accessible via `npm run` or `yarn`.

Configuration (package.json)

✓ { "typeCoverage": { "atLeast": 90, "threshold": 90 } }

✗ Placing `typeCoverage` options directly at the root of `package.json` or under an incorrect key.

Configuration options, such as the minimum coverage threshold, can be defined within `package.json` under the `typeCoverage` key, which the CLI tool will then read.

This quickstart demonstrates how to install `typescript-coverage-report`, configure a `package.json` script, and run the CLI tool to generate an HTML type coverage report for a basic TypeScript project, setting a custom threshold and output directory.

{ "name": "my-ts-project", "version": "1.0.0", "description": "A sample TypeScript project", "main": "dist/index.js", "scripts": { "build": "tsc", "ts-coverage": "typescript-coverage-report --threshold=95 --outputDir=./html-coverage" }, "keywords": [], "author": "", "license": "MIT", "devDependencies": { "typescript": "^5.0.0", "typescript-coverage-report": "^1.1.1" } } // Create a tsconfig.json file in the root: // { // "compilerOptions": { // "target": "ES2020", // "module": "CommonJS", // "strict": true, // "esModuleInterop": true, // "skipLibCheck": true, // "forceConsistentCasingInFileNames": true, // "outDir": "./dist" // }, // "include": ["src/**/*.ts"] // } // Create a sample TypeScript file (e.g., src/index.ts): // export function add(a: number, b: number): number { // return a + b; // } // export function subtract(a: any, b: number) { // // 'a' is implicitly 'any', reducing type coverage // return a - b; // } // Now run the coverage report: // npm install // npm run ts-coverage

Debug

Known issues

gotchaThe `typescript-coverage-report` tool has historically encountered compatibility issues with newer TypeScript versions shortly after their release (e.g., fixes for TS 4.x and 4.4 were needed in previous versions). While its `peerDependencies` are broad (2 || 3 || 4 || 5), new major TypeScript releases might introduce breaking changes to internal APIs that the tool relies on, potentially causing unexpected failures until `typescript-coverage-report` is updated.

fix

Before upgrading to a brand new major TypeScript version, check the `typescript-coverage-report` GitHub issues and releases for any known compatibility problems. Consider pinning your TypeScript version if encountering issues with the latest release.

affects: >=0.0.0

gotchaThe tool deletes the specified output directory (`coverage-ts` by default) before generating the new report. If you have custom files or other important data stored within this directory, they will be irrevocably lost without a warning.

fix

Always specify an `--outputDir` (or `outputDir` in `package.json`) that is exclusively used by `typescript-coverage-report` and contains no other critical files. Consider committing generated reports to version control only if necessary, and ensure a `.gitignore` entry for the output directory.

affects: >=0.5.0

gotchaOptions can be configured via CLI flags (e.g., `--threshold`) or through the `typeCoverage` section in `package.json` (e.g., `"atLeast": 90`). In most CLI tools, command-line arguments take precedence over file-based configurations. If conflicting values are provided, the CLI flag's value will likely override the `package.json` setting, which can lead to unexpected behavior.

fix

Choose one primary method for configuration (either CLI flags or `package.json`) and stick to it to avoid confusion. If both are used, be aware that CLI flags typically override `package.json` settings for the same option.

affects: >=0.0.0

gotchaIf your project's `tsconfig.json` is not located in the current working directory where the command is run, or if you have multiple `tsconfig.json` files, the tool may not correctly identify the project context. This can lead to an incomplete or inaccurate coverage report.

fix

Always explicitly specify the path to your `tsconfig.json` file using the `--project` CLI option, for example: `typescript-coverage-report --project ./path/to/my/tsconfig.json`.

affects: >=0.0.0

Errors

Common errors & fixes

Maximum call stack size exceeded

This error was a known bug in older versions (pre-0.5.1) of `typescript-coverage-report`, often triggered by analyzing large projects or specific complex code structures.

fix

Upgrade `typescript-coverage-report` to version 0.5.1 or newer to resolve this bug. `npm install typescript-coverage-report@latest`

Coverage threshold of XX% not met (found YY%)

The calculated type coverage percentage (YY%) for your project is below the minimum threshold (XX%) configured via `--threshold` or `typeCoverage.atLeast` in `package.json`.

fix

Increase the type coverage in your project by adding more explicit type annotations, or adjust the `--threshold` CLI option or `typeCoverage.atLeast` value in `package.json` to a lower, more realistic percentage.

`typescript-coverage-report` wrongly reports 100% of coverage in almost everything.

This can happen if the tool is not correctly configured to analyze all relevant files, or if `tsconfig.json` exclusions are too broad, leading to an incorrect perception of full coverage for partially typed files.

fix

Verify your `tsconfig.json`'s `include` and `exclude` paths. Ensure the `--project` option is pointing to the correct `tsconfig.json`. Check that the `type-coverage` configuration within `package.json` (which `typescript-coverage-report` uses) is set up to analyze all desired files and not implicitly ignoring types.

Syntax highlighter doesn't support emojis

A known bug in the internal code highlighter used by the generated HTML report does not correctly render or may break with emojis present in source code comments or strings.

fix

This is a minor display bug in the HTML report and does not affect the correctness of the coverage calculation. Avoid using emojis directly in your code if you rely on the HTML report's highlighting for these specific lines. There is no direct user fix beyond avoiding the problematic characters.

Upgrade

Version history

1.1.1latest on npm

Audit

Dependencies

typescriptrequiredPeer dependency, required for type analysis. The tool relies on the TypeScript compiler API.

Agent activity

43 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/alexcanessa/typescript-coverage-report ↗

packagehttps://www.npmjs.com/package/typescript-coverage-report ↗