File dependency debugging tool for TypeScript projects
Since you landed here, you might be also interested in my other project - supercharged multiline code search and replace tool - codeque.co 🥳
The tool was created help with daily dev struggles by answering these questions:
👉 What entry points my codebase have
👉 Which entry points uses a given file
👉 Which dependencies a given file has
This helps to debug project dependencies, plan refactoring, optimize bundles or plan code splitting.
It's especially useful in JS world without TypeScript or tests coverage.
It also helps to identify and eliminate dead files, understand the complexity of the file dependencies
- You plan to refactor some file and you wonder which entry points are affected
- You are wondering wether a given source file is used
- You wonder if there are any dead files in your project
- You want to verify if a given entry point imports only the required files
- You want to optimize the amount of files imported by an entry point
There are tool that can output nice, visual representation of project dependencies like webpack-bundle-analyzer or dependency-cruiser (which btw rev-dep uses for non-TS codebases)
While graphs can be useful to identify major problems like too big bundle size or to visualize mess in your deps, it's hard to take any action based on them (at least it was hard for me 🤷♂️)
rev-dep visualize dependencies as lists, so it's really easy to see where to cut the line to solve the problem.
yarn global add rev-dep
or
npm -g install rev-dep
yarn add rev-dep
or
npm install rev-dep
Just use rev-dep resolve path/to/file.ts
You will see all the entry points that implicitly require given file together with resolution path.
Example for the rev-dep repository
command:
rev-dep resolve src/lib/utils.ts
output:
src/babel/index.js :
➞ src/babel/index.js
➞ src/lib/utils.ts
_____________________
src/cli/index.ts :
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/resolve/index.ts
➞ src/lib/find.ts
➞ src/lib/getDepsTree.ts
➞ src/lib/getDepsSetWebpack.ts
➞ src/lib/utils.ts
_____________________
To find out all paths combination use rev-dep resolve with -a flag
You might be surprised how complex dependency tree can be!
Example for the rev-dep repository
command:
rev-dep resolve src/lib/utils.ts src/cli/index.ts --all
output:
src/cli/index.ts :
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/resolve/index.ts
➞ src/lib/find.ts
➞ src/lib/getDepsTree.ts
➞ src/lib/getDepsSetWebpack.ts
➞ src/lib/utils.ts
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/resolve/index.ts
➞ src/lib/find.ts
➞ src/lib/getEntryPoints.ts
➞ src/lib/getDepsTree.ts
➞ src/lib/getDepsSetWebpack.ts
➞ src/lib/utils.ts
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/entryPoints/index.ts
➞ src/lib/getEntryPoints.ts
➞ src/lib/getDepsTree.ts
➞ src/lib/getDepsSetWebpack.ts
➞ src/lib/utils.ts
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/files/index.ts
➞ src/lib/getDepsTree.ts
➞ src/lib/getDepsSetWebpack.ts
➞ src/lib/utils.ts
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/resolve/index.ts
➞ src/lib/find.ts
➞ src/lib/getEntryPoints.ts
➞ src/lib/utils.ts
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/entryPoints/index.ts
➞ src/lib/getEntryPoints.ts
➞ src/lib/utils.ts
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/resolve/index.ts
➞ src/lib/find.ts
➞ src/lib/utils.ts
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/resolve/index.ts
➞ src/lib/utils.ts
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/entryPoints/index.ts
➞ src/lib/utils.ts
➞ src/cli/index.ts
➞ src/cli/createCommands.ts
➞ src/cli/files/index.ts
➞ src/lib/utils.ts
Use rev-dep resolve path/to/file.ts --compactSummary
As a result you will see total amount of entry points requiring a given file.
Note that among the entry points list there might be some dead files importing the searched file
Example for the rev-dep repository
command:
rev-dep resolve src/lib/utils.ts --compactSummary
output:
Results:
__tests__/find.test.js : 0
babel.js : 0
bin.js : 0
scripts/addDocsToReadme.js : 0
src/babel/index.js : 1
src/cli/index.ts : 1
src/lib/getMaxDepthInGraph.ts : 0
types.d.ts : 0
Total: 2Use rev-dep entry-points to get list of all files that are not required by any other files in the project.
You might want to exclude some file paths that are meant to be actual entry point like index.js or **/pages/** in next.js projects using --exclude flag. The same for configuration files like babel.config.js
Review the list and look for suspicious files like src/ui/components/SomeComponent/index.js
entry-points command CLI reference
Example for the rev-dep repository
command:
rev-dep entry-points --exclude '__tests__/**' 'types.d.ts'
output:
babel.js
bin.js
scripts/addDocsToReadme.js
src/babel/index.js
src/cli/index.ts
src/lib/getMaxDepthInGraph.ts
The last one src/lib/getMaxDepthInGraph.ts is the source file that is not used at the moment.
The rest of them looks legit!
To get a full list of files imported by given entry point use rev-dep files path/to/file.ts.
You can use --count flag if you are interested in the amount.
This is a good indicator of how heavy a given entry point or component is
Example for the rev-dep repository
command:
rev-dep files files src/cli/index.ts
output:
src/cli/index.ts
src/cli/createCommands.ts
package.json
src/cli/resolve/index.ts
src/cli/docs/index.ts
src/cli/entryPoints/index.ts
src/cli/files/index.ts
src/lib/find.ts
src/cli/resolve/types.ts
src/cli/resolve/formatResults.ts
src/lib/utils.ts
src/cli/commonOptions.ts
src/cli/docs/generate.ts
src/cli/entryPoints/types.ts
src/lib/getEntryPoints.ts
src/lib/buildDepsGraph.ts
src/cli/files/types.ts
src/lib/getDepsTree.ts
src/lib/types.ts
src/cli/docs/template.ts
src/lib/getDepsSetWebpack.ts
src/lib/cleanupDpdmDeps.ts
As you can see cli even import package.json. This is to print version of the cli
There is no easy how to for this process, but you can do it iteratively using rev-dep commands files and resolve
-
Get the list of files imported by entry-point
rev-dep files path/to/entry-point -
Identify some suspicious files on the list, components that should not be used on the given page or not related utility files
-
Get all resolution paths for a suspicious file
rev-dep resolve path/to/suspicious-file path/to/entry-point --all -
You would usually find out that there is some file, like directory
indexfile that given entry point is using, which is mandatory, but as a side effect it imports a few files that are redundant for your entry point. In most cases you should be able to decouple the imports or reverse the dependency to cut off the resolution path for the unwanted file
Project can be used as a CLI tool or as a module
For CLI usage see CLI reference
import { resolve } from "rev-dep";
const [paths] = await resolve({
entryPoints: ["index.js"],
filePath: "utils.js",
});
console.log(paths);import { getEntryPoints } from "rev-dep";
const [entryPoints] = await getEntryPoints({
cwd: process.cwd(),
});
console.log(entryPoints);Checks if a filePath is required from entryPoint(s) and prints the resolution path
rev-dep resolve <filePathOrNodeModuleName> [entryPoints...] [options]filePathOrNodeModuleName- undefined (required)entryPoints...- List of entry points to look for file (optional)
-wc, --webpackConfig <path>- path to webpack config to enable webpack aliases support (optional)--cwd <path>- path to a directory that should be used as a resolution root (optional)-i --include <globs...>- A list of globs to determine files included in entry points search (optional)-e --exclude <globs...>- A list of globs to determine files excluded in entry points search (optional)-cs, --compactSummary- print a compact summary of reverse resolution with a count of found paths (optional)-a, --all- finds all paths combination of a given dependency. Might work very slow or crash for some projects due to heavy usage of RAM (optional)-ntp --notTraversePaths <paths...>- Specify file paths relative to resolution root, that should not be traversed when finding dependency path (optional)-inm --includeNodeModules- Whether to include node modules in dependency graph. Has to be provided to resolve node module. (optional)-iti --ignoreTypesImports- Use this flag to not follow type imports when resolving modules (optional)
Print list of entry points in current directory
rev-dep entry-points [options]-wc, --webpackConfig <path>- path to webpack config to enable webpack aliases support (optional)--cwd <path>- path to a directory that should be used as a resolution root (optional)-i --include <globs...>- A list of globs to determine files included in entry points search (optional)-e --exclude <globs...>- A list of globs to determine files excluded in entry points search (optional)-pdc, --printDependenciesCount- print count of entry point dependencies (optional)-c, --count- print just count of found entry points (optional)-iti --ignoreTypesImports- Use this flag to not follow type imports when resolving modules (optional)
Get list of files required by entry point
rev-dep files <entryPoint> [options]entryPoint- Path to entry point (required)
-wc, --webpackConfig <path>- path to webpack config to enable webpack aliases support (optional)--cwd <path>- path to a directory that should be used as a resolution root (optional)-c, --count- print only count of entry point dependencies (optional)-iti --ignoreTypesImports- Use this flag to not follow type imports when resolving modules (optional)
Get list of node modules required by entry point
rev-dep node-modules <entryPoint> [options]entryPoint- Path to entry point (required)
-wc, --webpackConfig <path>- path to webpack config to enable webpack aliases support (optional)--cwd <path>- path to a directory that should be used as a resolution root (optional)-c, --count- print only count of entry point dependencies (optional)-iti --ignoreTypesImports- Use this flag to not follow type imports when resolving modules (optional)
Generate documentation of available commands into md file.
rev-dep docs <outputPath> [options]outputPath- path to output *.md file (required)
-hl, --headerLevel <value>- Initial header level (optional)
rev-dep attempts to also solve export * from by a babel plugin that can be used as follows
// babel.config.js
module.exports = {
plugins: ["rev-dep/babel"],
};The plugins is currently experimental and might not work for all codebases!
It helps by rewiring paths to re-exported modules
// file.ts
import { add } from "./utils";
// utils/index.ts
export * from "./math";
export * from "./otherModule";
export * from "./anotherModule";
// utils/math.ts
export const add = () => {};And for file.ts it would rewire the import like this
// file.ts
import { add } from "./utils/math";So as a result, we don't implicitly require ./otherModule and ./anotherModule which we will not use anyway
I don't have solid evidence for this, but I think it reduced RAM usage of the dev server I worked with (blitz.js). It crashed less often due to reaching heap size limit.
But for sure it reduced bundle size, slightly, but still 😀
It all depends on the the project dependencies structure.
By using the babel plugin you will reduce a risk of problems like implicitly importing front-end modules on the server or similar while still being able to benefit from short import paths.
Once I got an incident that, after a rebase with main branch, my project stopped compiling due to the problem caused by export * from. I spend a few hours debugging that, very frustrating.
Project is open to contributions, just rise an issue if you have some ideas about features or you noticed a bug. After discussion we can approach implementation :)
- Clone repo
- Install deps using
yarn - Run
yarn build:watch - Code!
For testing purpose use
yarn dev [command] --cwd path/to/some/codebase
or you can install CLI tool from the file system using
yarn global add $PWD
and then just run
rev-dep
Made with 🧠 by @jayu
I hope that this small piece of software will help you discover and understood complexity of your project hence make you more confident while refactoring. If this tool was useful, don't hesitate to give it a ⭐!