feat: allow extracting of node+npm from package.json

[yoroshikun]

Quick PR for allowing extracting the node and npm version from packages.json

The "pkgx" node version will always have priority, over "engines" use.

I also modified the tests to allow for more than one requirement to be added in one pass, let me know if this is not so good.

Possible improvements.

• If pkgx is used it will take over and prevent npm requirement being added if it exists solely in engines. Maybe only check for if a node version is added to the deps.

Help

What is the correct way to test the dev function on real projects, do i need to install the build pkgx version and it should use that instead of needing to rebootstrap?

[mxcl]

LGTM! Thank you.

The "pkgx" node version will always have priority, over "engines" use.

I believe constraints are combined so any of them refine the others. Conflicts lead to error eg. one asks for node 16 the other node 18, but if one asks for ^16 and the other ~16.1 then the are combined (in this case the overlap is ~16.1).

I say “believe” rather than know because I'm pretty sure but didn't review the code and wrote it a while back (in mental terms).

If pkgx is used it will take over and prevent npm requirement being added if it exists solely in engines. Maybe only check for if a node version is added to the deps.

Not sure I understand you here.

What is the correct way to test the dev function on real projects, do i need to install the build pkgx version and it should use that instead of needing to rebootstrap?

deno task install

Will install your checkout to /usr/local/bin. dev uses that. Then just step into a dev-enabled directory.

[yoroshikun]

If pkgx is used it will take over and prevent npm requirement being added if it exists solely in engines. Maybe only check for if a node version is added to the deps.

@mxcl examples are probs easier.

Currently the code works like this

{
  "engines": {
    "node": "~16.16.1",
    "npm": "~9.7.1"
  }
}

Resolved, nodejs.org~16.16.1,npmjs.com~9.7.1

{
  "pkgx": "zlib@1.1.1",
  "engines": {
    "node": "~16.16.1",
    "npm": "~9.7.1"
  }
}

Resolved zlib@1.1.1 (only)

since pkgx takes priority.

Based on this I plan to make a follow up PR (or few) to make this a bit more robust at choosing and combining correctly in the packagejson helper.

[mxcl]

Based on how we are handling other such situations we should not remove the computed engines if there is a pkgx node. If the user specifies (eg) node in both places then we attempt to consolidate them (this is done for you automatically), if they cannot be combined into a single range it throws.