javascript - How to add dev-only dependencies in Deno? - Stack Overflow

admin管理员组

文章数量:1026087

In Node.js, we can use npm install -D foo to add a dependency into package.json > devDependencies. When the package is published and used as a dependency, devDependencies won't be installed.

But in deno.json, there is only imports, no devImports. According to Deno v2 RC announcement, we can use deno add --dev. But this only add contents to deno.lock, not adding anything to deno.json. I tried deno add --dev eslint (not migrating Deno Lint yet), but it complained eslint: command not found.

When package.json exists, it's added to package.json, but I'm trying finding a pure-Deno solution.

I found denoland/deno#26865, but no answers are there.

In Node.js, we can use npm install -D foo to add a dependency into package.json > devDependencies. When the package is published and used as a dependency, devDependencies won't be installed.

But in deno.json, there is only imports, no devImports. According to Deno v2 RC announcement, we can use deno add --dev. But this only add contents to deno.lock, not adding anything to deno.json. I tried deno add --dev eslint (not migrating Deno Lint yet), but it complained eslint: command not found.

When package.json exists, it's added to package.json, but I'm trying finding a pure-Deno solution.

I found denoland/deno#26865, but no answers are there.

• javascript
• dependencies
• deno

Share Improve this question Follow edited Nov 20, 2024 at 12:34 typed-sigterm asked Nov 17, 2024 at 12:19 typed-sigtermtyped-sigterm 1,2471111 silver badges3535 bronze badges 3

• "…install a dev-only dependency": Can you edit the question to clarify what is meant by "install"? Are you referring to the specific scenario of using npm dependencies while using package.json and a local node_modules directory? By default, Deno downloads imported module data into an immutable, global cache. Read more at the docs: Modules and dependencies – jsejcksn Commented Nov 19, 2024 at 23:18
• @jsejcksn Edited. I'm just finding a thing in Deno like devDependencies in Node.js/npm – typed-sigterm Commented Nov 20, 2024 at 12:38
• 1 Looks like there is no option to add a package as a dev dependency for packages published on JSR. The --dev flag works only for packages published on npm and requires package.json file. Find out more information in the reply of the GitHub issue you have linked: github/denoland/deno/issues/26865#issuecomment-2480833535 – Kotkoroid Commented Nov 21, 2024 at 16:58

Add a comment  | 

1 Answer 1

Sorted by: Reset to default 4

See this answer by "crowKats" here, but in short:

With a “npm-style” Deno project, based on package.json, use

• deno add --dev for dev dependencies, or
• deno add for production dependencies.

But with a deno.json or deno.jsonc project, use

• deno add, in either case.

There’s no need to segregate development and production dependencies for Deno 2+ native projects. Deno is smart: it only caches and installs the dependencies needed for the current runtime.

While I’m not a Deno expert myself (still learning), my suggestion is that you need to read Deno's documentation attentively but also with an "open mind" (don't expect it to just be a cuter, giant-lizard version of npm):

• In the npm world, npm install is required before running any project, otherwise the application will break: dependencies wont't be available in node_modules when some code tries to access it.

• With Deno-style though, there is no node_modules; nevertheless, dependencies will also be cached automatically at runtime. You can (and should, especially in production) run deno cache ahead of time, of course - so you can prepopulate the cache with all identified packages, before they are used. But if you, say, add a new dependency or make a hotfix change in production, Deno's expected behaviour is to detect it, automatically download the dependency to its cache, and continue executing the application without further interruption.

• To make things even weirder, this also means not even deno add is really required. According to Deno's docs, imports in the code should be "unequivocal": e.g. they must specify the package registry or source - with the npm:, node: or jsr: prefixes, for example. And this "extra" info is enough for Deno's runtime to repopulate its cache on demand.

References:

• https://medium/deno-the-complete-reference/dependency-installation-in-deno-41caf01ec903
• https://docs.deno/examples/node_built_in/
• https://docs.deno/runtime/fundamentals/node/

In Node.js, we can use npm install -D foo to add a dependency into package.json > devDependencies. When the package is published and used as a dependency, devDependencies won't be installed.

But in deno.json, there is only imports, no devImports. According to Deno v2 RC announcement, we can use deno add --dev. But this only add contents to deno.lock, not adding anything to deno.json. I tried deno add --dev eslint (not migrating Deno Lint yet), but it complained eslint: command not found.

When package.json exists, it's added to package.json, but I'm trying finding a pure-Deno solution.

I found denoland/deno#26865, but no answers are there.

In Node.js, we can use npm install -D foo to add a dependency into package.json > devDependencies. When the package is published and used as a dependency, devDependencies won't be installed.

But in deno.json, there is only imports, no devImports. According to Deno v2 RC announcement, we can use deno add --dev. But this only add contents to deno.lock, not adding anything to deno.json. I tried deno add --dev eslint (not migrating Deno Lint yet), but it complained eslint: command not found.

When package.json exists, it's added to package.json, but I'm trying finding a pure-Deno solution.

I found denoland/deno#26865, but no answers are there.

• javascript
• dependencies
• deno

Share Improve this question Follow edited Nov 20, 2024 at 12:34 typed-sigterm asked Nov 17, 2024 at 12:19 typed-sigtermtyped-sigterm 1,2471111 silver badges3535 bronze badges 3

• "…install a dev-only dependency": Can you edit the question to clarify what is meant by "install"? Are you referring to the specific scenario of using npm dependencies while using package.json and a local node_modules directory? By default, Deno downloads imported module data into an immutable, global cache. Read more at the docs: Modules and dependencies – jsejcksn Commented Nov 19, 2024 at 23:18
• @jsejcksn Edited. I'm just finding a thing in Deno like devDependencies in Node.js/npm – typed-sigterm Commented Nov 20, 2024 at 12:38
• 1 Looks like there is no option to add a package as a dev dependency for packages published on JSR. The --dev flag works only for packages published on npm and requires package.json file. Find out more information in the reply of the GitHub issue you have linked: github/denoland/deno/issues/26865#issuecomment-2480833535 – Kotkoroid Commented Nov 21, 2024 at 16:58

Add a comment  | 

1 Answer 1

Sorted by: Reset to default 4

See this answer by "crowKats" here, but in short:

With a “npm-style” Deno project, based on package.json, use

• deno add --dev for dev dependencies, or
• deno add for production dependencies.

But with a deno.json or deno.jsonc project, use

• deno add, in either case.

There’s no need to segregate development and production dependencies for Deno 2+ native projects. Deno is smart: it only caches and installs the dependencies needed for the current runtime.

While I’m not a Deno expert myself (still learning), my suggestion is that you need to read Deno's documentation attentively but also with an "open mind" (don't expect it to just be a cuter, giant-lizard version of npm):

• In the npm world, npm install is required before running any project, otherwise the application will break: dependencies wont't be available in node_modules when some code tries to access it.

• With Deno-style though, there is no node_modules; nevertheless, dependencies will also be cached automatically at runtime. You can (and should, especially in production) run deno cache ahead of time, of course - so you can prepopulate the cache with all identified packages, before they are used. But if you, say, add a new dependency or make a hotfix change in production, Deno's expected behaviour is to detect it, automatically download the dependency to its cache, and continue executing the application without further interruption.

• To make things even weirder, this also means not even deno add is really required. According to Deno's docs, imports in the code should be "unequivocal": e.g. they must specify the package registry or source - with the npm:, node: or jsr: prefixes, for example. And this "extra" info is enough for Deno's runtime to repopulate its cache on demand.

References:

• https://medium/deno-the-complete-reference/dependency-installation-in-deno-41caf01ec903
• https://docs.deno/examples/node_built_in/
• https://docs.deno/runtime/fundamentals/node/

本文标签： javascriptHow to add devonly dependencies in DenoStack Overflow