modular typecheck [options] [packages...]

modular typecheck will programmatically report the semantic, syntactic, and declaration type errors found in your code, based on your tsconfig.json.

In a CI environment, it will print condensed errors if they are present.

In non-CI environments, it will print the full details of the error, line, and small snapshot of the offending line in question.

Configuration

modular typecheck will respect the root tsconfig.json, but most compilerOptions are ignored.

It should be noted that modular typecheck does not support package-level tsconfig.json files, for backwards compatibility. Your IDE may still consume these, but it is recommended to keep your TypeScript configuration in the root tsconfig.json.

Why does Modular restrict compilerOptions?

modular typecheck aims to verify that the project’s types are passing without errors. Certain TypeScript features such as emitting output are not useful in this scenario, so Modular has always applied a restricted set of compilerOptions.

Although this approach has limited flexibility, it fits with Modular’s goals and brings certain advantages:

• Configuration is kept minimal and simple where possible
• The possibility of incompatible or conflicting compilerOptions between packages is avoided
• It enables the use of selective modular typecheck (i.e. supply package names and using flags such as --ancestors)

There are certain exceptions for practical use cases. The current allowlist is:

• jsx
• strict

Some use cases may warrant new exceptions. If this is you, please file an issue with the project for consideration.

Command line options and arguments

Default Behavior

modular typecheck without any options will typecheck all packages

Non Modular Packages

If non modular packages (packages without a modular field in their package.json) are included in the selection, Modular will attempt to run the typecheck script in their package.json if specified.

Selective Options

--descendants: Typecheck the packages specified by the [packages...] argument and/or the --changed option and additionally typecheck all their descendants (i.e. the packages they directly or indirectly depend on).

--ancestors: Typecheck the packages specified by the [packages...] argument and/or the --changed option and additionally typecheck all their ancestors (i.e. the packages that have a direct or indirect dependency on them).

--changed: Typecheck only the packages whose workspaces contain files that have changed. Files that have changed are calculated comparing the current state of the repository with the branch specified by compareBranch or, if compareBranch is not set, with the default git branch.

--compareBranch: Specify the comparison branch used to determine which files have changed when using the changed option. If this option is used without changed, the command will fail.

Other options

--verbose: Enables verbose logging within modular