bare-addon-resolve

Low-level addon resolution algorithm for Bare. The algorithm is implemented as a generator function that yields either package manifests to be read or resolution candidates to be tested by the caller. As a convenience, the main export is a synchronous and asynchronous iterable that relies on package manifests being read by a callback. For asynchronous iteration, the callback may return promises which will be awaited before being passed to the generator.

npm i bare-addon-resolve

Usage

For synchronous resolution:

const resolve = require('bare-addon-resolve')

function readPackage(url) {
  // Read and parse `url` if it exists, otherwise `null`
}

for (const resolution of resolve('./addon', new URL('file:///directory/'), readPackage)) {
  console.log(resolution)
}

For asynchronous resolution:

const resolve = require('bare-addon-resolve')

async function readPackage(url) {
  // Read and parse `url` if it exists, otherwise `null`
}

for await (const resolution of resolve('./addon', new URL('file:///directory/'), readPackage)) {
  console.log(resolution)
}

API

See the bare-addon-resolve reference.

Algorithm

The following generator functions implement the resolution algorithm. The yielded values have the following shape:

Package manifest

next.value = {
  package: URL
}

If the package manifest identified by next.value.package exists, generator.next() must be passed the parsed JSON value of the manifest. If it does not exist, pass null instead.

Resolution candidate

next.value = {
  resolution: URL
}

If the addon identified by next.value.resolution exists, generator.next() may be passed true to signal that the resolution for the current set of conditions has been identified. If it does not exist, pass false instead.

To drive the generator functions, a loop like the following can be used:

const generator = resolve.addon(specifier, parentURL)

let next = generator.next()

while (next.done !== true) {
  const value = next.value

  if (value.package) {
    // Read and parse `value.package` if it exists, otherwise `null`
    let info

    next = generator.next(info)
  } else {
    const resolution = value.resolution

    // `true` if `resolution` was the correct candidate, otherwise `false`
    let resolved

    next = generator.next(resolved)
  }
}

Options are the same as resolve() for all functions.

[!WARNING] These functions are currently subject to change between minor releases. If using them directly, make sure to specify a tilde range (~1.2.3) when declaring the module dependency.

The preresolved, builtinTarget, and lookupPackageScope generators referenced below are provided by bare-module-resolve and behave as documented there.

const generator = resolve.addon(specifier, parentURL[, options])

1. If specifier starts with a Windows drive letter:
   1. Prepend / to specifier.
2. If options.resolutions is set:
   1. If preresolved(specifier, options.resolutions, parentURL, options) yields a resolution that isn't deferred, return.
3. If url(specifier, parentURL, options) yields, return.
4. Let version be null.
5. Let i be the index of the last @ in specifier.
6. If i is greater than 0:
   1. Set version to the substring of specifier following i.
   2. If version is a valid semantic version:
      1. Set specifier to the substring of specifier until i.
   3. Otherwise, set version to null.
7. If specifier equals . or .., or if specifier starts with /, \, ./, .\, ../, or ..\:
   1. If file(specifier, parentURL, options) resolves, return.
   2. Return directory(specifier, version, parentURL, options).
8. Return package(specifier, version, parentURL, options).

const generator = resolve.url(url, parentURL[, options])

1. If url is not a valid URL, return.
2. Yield url.

const generator = resolve.package(packageSpecifier, packageVersion, parentURL[, options])

1. If packageSpecifier is the empty string, throw.
2. If packageSpecifier does not start with @:
   1. Set packageName to the substring of packageSpecifier until the first / or the end of the string.
3. Otherwise:
   1. If packageSpecifier does not include /, throw.
   2. Set packageName to the substring of packageSpecifier until the second / or the end of the string.
4. If packageName starts with . or includes \ or %, throw.
5. Let packageSubpath be . concatenated with the substring of packageSpecifier from the position at the length of packageName.
6. If parentURL has an opaque path, return.
7. If packageSelf(packageName, packageSubpath, packageVersion, parentURL, options) yields, return.
8. Repeat:
   1. Let packageURL be the resolution of node_modules/ concatenated with packageName and / relative to parentURL.
   2. Set parentURL to its parent directory.
   3. Let info be the result of yielding the resolution of package.json relative to packageURL.
   4. If info is not null:
      1. Return directory(packageSubpath, packageVersion, packageURL, options).
   5. If the path of parentURL is empty or /, return.

const generator = resolve.packageSelf(packageName, packageSubpath, packageVersion, parentURL[, options])

1. For each value packageURL of lookupPackageScope(parentURL, options):
   1. Let info be the result of yielding packageURL.
   2. If info is not null:
      1. If info.name does not equal packageName, return.
      2. Return directory(packageSubpath, packageVersion, packageURL, options).

const generator = resolve.file(filename, parentURL[, options])

1. If filename equals . or .., or if filename ends with / or \, return.
2. If parentURL has an opaque path, return.
3. If parentURL is a file: URL and filename includes encoded / or \, throw.
4. For each value ext of options.extensions:
   1. If filename ends with ext, set ext to the empty string.
   2. Yield the resolution of filename concatenated with ext relative to parentURL; if it resolves, return.

const generator = resolve.directory(dirname, version, parentURL[, options])

1. If parentURL has an opaque path, return.
2. If dirname ends with / or \:
   1. Let directoryURL be the resolution of dirname relative to parentURL.
3. Otherwise:
   1. Let directoryURL be the resolution of dirname concatenated with / relative to parentURL.
4. Let unversioned be true if version is null, otherwise false.
5. Let info be the result of yielding the resolution of package.json relative to directoryURL.
6. If info is null, return.
7. If info.name is a non-empty string:
   1. If info.name includes __, throw.
   2. Let name be info.name with every / replaced by __ and any leading @ removed.
8. Otherwise, return.
9. If info.version is a non-empty string:
   1. If version is not null and info.version does not equal version, return.
   2. Set version to info.version.
10. If builtinTarget(name, version, options.builtins, options) yields, return.
11. Let native be the values of options.hosts that do not start with wasi-, and wasm the values that do.
12. If prebuilds(name, version, unversioned, directoryURL, native, options) resolves, return.
13. If linked(name, version, options) resolves, return.
14. Return prebuilds(name, version, unversioned, directoryURL, wasm, options) with options.extensions set to ['.wasm'].

const generator = prebuilds(name, version, unversioned, directoryURL, hosts, options)

1. For each value prebuildsURL of lookupPrebuildsScope(directoryURL, options):
   1. Let resolved be false.
   2. For each value host of hosts:
      1. Let conditions be the result of splitting host on -.
      2. If host is one of darwin-arm64, darwin-x64, ios-arm64-simulator, or ios-x64-simulator, let universal be host with its second component replaced by universal; otherwise let universal be null.
      3. Append the values of conditions to options.matchedConditions.
      4. If version is not null:
         1. If file(host + '/' + name + '@' + version, prebuildsURL, options) resolves, set resolved to true.
         2. If universal is not null and file(universal + '/' + name + '@' + version, prebuildsURL, options) resolves, set resolved to true.
      5. If unversioned is true:
         1. If file(host + '/' + name, prebuildsURL, options) resolves, set resolved to true.
         2. If universal is not null and file(universal + '/' + name, prebuildsURL, options) resolves, set resolved to true.
      6. Remove the values of conditions from options.matchedConditions.
   3. If resolved is true, return.

const generator = resolve.linked(name, version[, options])

1. If options.linked is false or options.hosts is empty, return.
2. For each value host of options.hosts:
   1. Let platform be the substring of host until the first -.
   2. If platform is the empty string, continue.
   3. Append platform to options.matchedConditions.
   4. Let candidates be the following artefact names, in order, where each entry containing <version> is only included when version is not null:
      1. If platform is darwin or ios:
         1. <name>.<version>.framework/<name>.<version>
         2. lib<name>.<version>.dylib, only if platform is darwin
         3. <name>.framework/<name>
         4. lib<name>.dylib, only if platform is darwin
      2. Otherwise, if platform is linux or android:
         1. lib<name>.<version>.so
         2. lib<name>.so
      3. Otherwise, if platform is win32:
         1. <name>-<version>.dll
         2. <name>.dll
   5. For each value candidate of candidates:
      1. Yield options.linkedProtocol concatenated with candidate; if it resolves, stop iterating candidates.
   6. Remove platform from options.matchedConditions.

License

Apache-2.0