Skip to content
This repository has been archived by the owner on Apr 16, 2020. It is now read-only.

Commit

Permalink
linting fixes
Browse files Browse the repository at this point in the history
  • Loading branch information
@guybedford
guybedford committed Nov 6, 2018
1 parent 7da2197 commit 1a021ec
Show file tree
Hide file tree
Showing 3 changed files with 63 additions and 36 deletions.
81 changes: 53 additions & 28 deletions doc/api/esm.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -142,10 +142,6 @@ fs.readFileSync = () => Buffer.from('Hello, ESM');
fs.readFileSync === readFileSync;
```
[Node.js EP for ES Modules]: https://github.com/nodejs/node-eps/blob/master/002-es-modules.md
[`module.createRequireFromPath()`]: modules.html#modules_module_createrequirefrompath_filename
[ESM Minimal Kernel]: https://github.com/nodejs/modules/blob/master/doc/plan-for-new-modules-implementation.md
## Resolution Algorithm
### Features
Expand All @@ -157,41 +153,57 @@ The resolver has the following properties:
* Relative and absolute URL resolution
* No default extensions
* Bare specifier package resolution lookup through node_modules
* Avoids the package fallback which breaks package isolation. This is the problem that an import to `x/y.js` will keep checking subsequent node_modules even if a package "x" is found without a "y.js". This is done through package name format detection.
* Avoids the package fallback which breaks package isolation. This is the
problem that an import to `x/y.js` will keep checking subsequent node_modules
even if a package "x" is found without a "y.js". This is done through package
name format detection.
The ESM resolver differs from the CommonJS resolver in detecting a package name based on it being either `package` or `@scoped/package`. This allows the resolver to know when a package has been matched, and then avoid a fallback for missing modules.
The ESM resolver differs from the CommonJS resolver in detecting a package name
based on it being either `package` or `@scoped/package`. This allows the
resolver to know when a package has been matched, and then avoid a fallback for
missing modules.
The main lookup is then provided by _CHECK_PACKAGE_MAIN_ which is still an experimental approach under discussion.
The main lookup is then provided by _CHECK_PACKAGE_MAIN_ which is still an
experimental approach under discussion.
Currently, the main lookup will only check for _index.mjs_.
### Examples
Relative and absolute resolution without directory or extension resolution (URL resolution):
Relative and absolute resolution without directory or extension resolution
(URL resolution):
* ESM_RESOLVE(_"./a.asdf"_, _"file:///parent/path"_) -> _file:///parent/a.asdf_
* ESM_RESOLVE(_"/a"_, _"file:///parent/path"_) -> _file:///a_
* ESM_RESOLVE(_"file:///a"_, _"file:///parent/path"_) -> _file:///a_
* ESM_RESOLVE("./a.asdf", "file:///parent/path") -> "file:///parent/a.asdf"
* ESMRESOLVE("/a", "file:///parent/path") -> "file:///a"
* ESMRESOLVE("file:///a", "file:///parent/path") -> "file:///a"
Package resolution:
1. ESM_RESOLVE(_"pkg/x"_, _"file:///path/to/project"_) -> _file:///path/to/node_modules/pkg/x_ (if it exists)
1. ESM_RESOLVE(_"pkg/x"_, _"file:///path/to/project"_) -> _Not Found_ otherwise, even if _file:///path/node_modules/pkg/x_ exists.
1. ESMRESOLVE("pkg/x", "file:///path/to/project") ->
"file:///path/to/nodemodules/pkg/x" (if it exists)
1. ESMRESOLVE("pkg/x", "file:///path/to/project") ->
Not Found otherwise, even if "file:///path/nodemodules/pkg/x" exists.
Main resolution:
1. ESM_RESOLVE(_"pkg"_, _"file:///path/to/project"_) -> _file:///path/to/project/node_modules/pkg/index.mjs_ (if it exists)
1. ESM_RESOLVE(_"pkg"_, _"file:///path/to/project"_) -> _Not Found_ otherwise, even if _file:///path/to/node_modules/pkg/index.mjs_ exists.
1. ESM_RESOLVE(_"file:///path/to/project"_) -> _file:///path/to/project/index.mjs_ (if it exists)
1. ESM_RESOLVE(_"file:///path/to/project"_) -> _Not Found_, if _file:///path/to/project/index.mjs_ does not exist.
1. ESMRESOLVE("pkg", "file:///path/to/project") ->
"file:///path/to/project/nodemodules/pkg/index.mjs" (if it exists)
1. ESMRESOLVE("pkg", "file:///path/to/project") -> Not Found otherwise,
even if "file:///path/to/nodemodules/pkg/index.mjs" exists.
1. ESMRESOLVE("file:///path/to/project") ->
"file:///path/to/project/index.mjs" (if it exists)
1. ESMRESOLVE("file:///path/to/project") ->
Not Found, if "file:///path/to/project/index.mjs" does not exist.
### Resolver Algorithm
The algorithm to resolve an ES module specifier is provided through _ESM_RESOLVE_:
The algorithm to resolve an ES module specifier is provided through
_ESM_RESOLVE_:
**ESM_RESOLVE**(_specifier_, _parentURL_)
> 1. If _specifier_ is a valid URL then,
> 1. Let _resolvedURL_ be the result of parsing and reserializing _specifier_ as a URL.
> 1. Let _resolvedURL_ be the result of parsing and reserializing
> _specifier_ as a URL.
> 1. Return the result of **PATH_RESOLVE**(_resolvedURL_).
> 1. If _specifier_ starts with _"/"_, _"./"_ or _"../"_ then,
> 1. Let _resolvedURL_ be the URL resolution of _specifier_ to _parentURL_.
Expand All @@ -202,7 +214,8 @@ The algorithm to resolve an ES module specifier is provided through _ESM_RESOLVE
**PATH_RESOLVE**(_resolvedURL_)
> 1. If the file at _resolvedURL_ exists then,
> 1. Return _resolvedURL_.
> 1. Let _packageMainURL_ be the result of **PACKAGE_MAIN_RESOLVE**(_resolvedURL_).
> 1. Let _packageMainURL_ be the result of
> **PACKAGE_MAIN_RESOLVE**(_resolvedURL_).
> 1. If _packageMainURL_ is not _undefined_ then,
> 1. Return _packageMainURL_.
> 1. Throw a _Module Not Found_ error.
Expand All @@ -214,30 +227,38 @@ The algorithm to resolve an ES module specifier is provided through _ESM_RESOLVE
> 1. Let _packageName_ be _undefined_.
> 1. Let _packagePath_ be _undefined_.
> 1. If _packageSpecifier_ does not start with _"@"_ then,
> 1. Set _packageName_ to the substring of _packageSpecifier_ until the first _"/"_ separator or the end of the string.
> 1. Set _packageName_ to the substring of _packageSpecifier_ until the
> first _"/"_ separator or the end of the string.
> 1. If _packageSpecifier_ starts with _"@"_ then,
> 1. If _packageSpecifier_ does not contain a _"/"_ separator then,
> 1. Throw a _Invalid Package Name_ error.
> 1. Set _packageName_ to the substring of _packageSpecifier_ until the second _"/"_ separator or the end of the string.
> 1. Let _packagePath_ be the substring of _packageSpecifier_ from the position at the length of _packageName_ plus one, if any.
> 1. Set _packageName_ to the substring of _packageSpecifier_
> until the second _"/"_ separator or the end of the string.
> 1. Let _packagePath_ be the substring of _packageSpecifier_ from the
> position at the length of _packageName_ plus one, if any.
> 1. Assert: _packageName_ is a valid package name or scoped package name.
> 1. Assert: _packagePath_ is either empty, or a path without a leading separator.
> 1. Assert: _packagePath_ is either empty, or a path without a leading
> separator.
> 1. Note: Further package name encoding validations can be added here.
> 1. If _packagePath_ is empty and _packageName_ is a Node.js builtin module then,
> 1. If _packagePath_ is empty and _packageName_ is a Node.js builtin
> module then,
> 1. Return _"node:${packageName}"_.
> 1. Set _parentURL_ to the parent folder URL of _parentURL_.
> 1. While _parentURL_ contains a non-empty _pathname_,
> 1. Let _packageURL_ be the URL resolution of _"${parentURL}/node_modules/${packageName}"_.
> 1. Let _packageURL_ be the URL resolution of
> _"${parentURL}/node_modules/${packageName}"_.
> 1. If the folder at _packageURL_ does not exist then,
> 1. Note: This check can be optimized out where possible in implementation.
> 1. Note: This check can be optimized out where possible in
> implementation.
> 1. Set _parentURL_ to the parent URL path of _parentURL_.
> 1. Continue the next loop iteration.
> 1. If _packagePath_ is empty then,
> 1. Let _url_ be the result of **PACKAGE_MAIN_RESOLVE**(_packageURL_).
> 1. If _url_ is not _undefined_ then,
> 1. Return _url_.
> 1. Otherwise,
> 1. Let _url_ be equal to the URL resolution of _packagePath_ in _packageURL_.
> 1. Let _url_ be equal to the URL resolution of _packagePath_ in
> _packageURL_.
> 1. If the file at _url_ exists then,
> 1. Return _url_.
> 1. Otherwise, if _url_ is a directory then,
Expand All @@ -252,3 +273,7 @@ The algorithm to resolve an ES module specifier is provided through _ESM_RESOLVE
> 1. Return _"${packageURL}/index.mjs"_.
> 1. Return _undefined_.
[Node.js EP for ES Modules]: https://github.com/nodejs/node-eps/blob/master/002-es-modules.md
[`module.createRequireFromPath()`]: modules.html#modules_module_createrequirefrompath_filename
[ESM Minimal Kernel]: https://github.com/nodejs/modules/blob/master/doc/plan-for-new-modules-implementation.md
3 changes: 2 additions & 1 deletion lib/internal/modules/esm/default_resolve.js
View file
Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,8 @@ function search(target, base) {
tmpMod.paths = CJSmodule._nodeModulePaths(
new URL('./', questionedBase).pathname);
const found = CJSmodule._resolveFilename(target, tmpMod);
error = new ERR_MODULE_RESOLUTION_LEGACY(target, fileURLToPath(base), found);
error = new ERR_MODULE_RESOLUTION_LEGACY(target,
fileURLToPath(base), found);
} catch {
// ignore
}
Expand Down
15 changes: 8 additions & 7 deletions src/module_wrap.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -508,7 +508,7 @@ Maybe<URL> PackageResolve(Environment* env,
}
sep_index = specifier.find('/', sep_index + 1);
}
std::string pkg_name = specifier.substr(0,
std::string pkg_name = specifier.substr(0,
sep_index == std::string::npos ? std::string::npos : sep_index);
std::string pkg_path;
if (sep_index == std::string::npos ||
Expand Down Expand Up @@ -554,9 +554,9 @@ Maybe<URL> PackageResolve(Environment* env,
return Nothing<URL>();
}

Maybe<URL> PathResolve (Environment* env,
const URL& url,
const URL& base) {
Maybe<URL> PathResolve(Environment* env,
const URL& url,
const URL& base) {
std::string path = url.ToFilePath();
DescriptorType check = CheckDescriptor(path);
if (check == FILE) return Just(url);
Expand Down Expand Up @@ -606,14 +606,15 @@ void ModuleWrap::Resolve(const FunctionCallbackInfo<Value>& args) {
return node::THROW_ERR_INVALID_ARG_TYPE(
env, "second argument is not a URL string");
}

TryCatch try_catch(env->isolate());
Maybe<URL> result = node::loader::Resolve(env, specifier_std, url);
if (try_catch.HasCaught()) {
try_catch.ReThrow();
return;
} else if (result.IsNothing() || (result.FromJust().flags() & URL_FLAGS_FAILED)) {
std::string msg = "Cannot find module '" + specifier_std +
} else if (result.IsNothing() ||
(result.FromJust().flags() & URL_FLAGS_FAILED)) {
std::string msg = "Cannot find module '" + specifier_std +
"' imported from " + url.ToFilePath();
node::THROW_ERR_MISSING_MODULE(env, msg.c_str());
try_catch.ReThrow();
Expand Down

0 comments on commit 1a021ec

Please sign in to comment.