JSON Modules #255

MylesBorins · 2019-01-22T20:13:24Z

I've opened this up on the whatwg/HTML repo.

Trying to figure out steps to supporting importing JSON

With the new flag `--experimental-json-modules` it is now possible to import .json files. It piggy backs on the current cjs loader implementation, so it only exports a default. This is a bit of a hack, and it should potentially have it's own loader, especially if we change the cjs loader at all. The behavior for .json in the cjs loader matches the current planned behavior if json modules were to be standardized, specifically that a .json module only exports a default. Refs: nodejs/modules#255 Refs: whatwg/html#4315 Refs: WICG/webcomponents#770

MylesBorins · 2019-02-26T19:11:51Z

rough implementation in nodejs/ecmascript-modules#43

With the new flag `--experimental-json-modules` it is now possible to import .json files. It piggy backs on the current cjs loader implementation, so it only exports a default. This is a bit of a hack, and it should potentially have it's own loader, especially if we change the cjs loader at all. The behavior for .json in the cjs loader matches the current planned behavior if json modules were to be standardized, specifically that a .json module only exports a default. Refs: nodejs/modules#255 Refs: whatwg/html#4315 Refs: WICG/webcomponents#770

This PR updates the current `--experimental-modules` implementation based on the work of the modules team and reflects Phase 2 of our new modules plan. The largest differences from the current implementation include * `packge.type` which can be either `module` or `commonjs` - `type: "commonjs"`: - `.js` is parsed as commonjs - default for entry point without an extension is commonjs - `type: "module"`: - `.js` is parsed as esm - does not support loading JSON or Native Module by default - default for entry point without an extension is esm * `--entry-type=[mode]` - allows you set the type on entry point. * A new file extension `.cjs`. - this is specifically to support importing commonjs in the `module` mode. - this is only in the esm loader, the commonjs loader remains untouched, but the extension will work in the old loader if you use the full file path. * `--es-module-specifier-resolution=[type]` - options are `explicit` (default) and `node` - by default our loader will not allow for optional extensions in the import, the path for a module must include the extension if there is one - by default our loader will not allow for importing directories that have an index file - developers can use `--es-module-specifier-resolution=node` to enable the commonjs specifier resolution algorithm - This is not a “feature” but rather an implementation for experimentation. It is expected to change before the flag is removed * `--experimental-json-loader` - the only way to import json when `"type": "module"` - when enable all `import 'thing.json'` will go through the experimental loader independent of mode - based on whatwg/html#4315 * You can use `package.main` to set an entry point for a module - the file extensions used in main will be resolved based on the `type` of the module Refs: https://github.com/nodejs/modules/blob/master/doc/plan-for-new-modules-implementation.md Refs: https://github.com/GeoffreyBooth/node-import-file-specifier-resolution-proposal Refs: nodejs/modules#180 Refs: nodejs/ecmascript-modules#6 Refs: nodejs/ecmascript-modules#12 Refs: nodejs/ecmascript-modules#28 Refs: nodejs/modules#255 Refs: whatwg/html#4315 Refs: WICG/webcomponents#770 Co-authored-by: Myles Borins <MylesBorins@google.com> Co-authored-by: John-David Dalton <john.david.dalton@gmail.com> Co-authored-by: Evan Plaice <evanplaice@gmail.com> Co-authored-by: Geoffrey Booth <webmaster@geoffreybooth.com> Co-authored-by: Michaël Zasso <targos@protonmail.com> PR-URL: nodejs#26745 Reviewed-By: Gus Caplan <me@gus.host> Reviewed-By: Guy Bedford <guybedford@gmail.com> Reviewed-By: Ben Coe <bencoe@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>

This PR updates the current `--experimental-modules` implementation based on the work of the modules team and reflects Phase 2 of our new modules plan. The largest differences from the current implementation include * `packge.type` which can be either `module` or `commonjs` - `type: "commonjs"`: - `.js` is parsed as commonjs - default for entry point without an extension is commonjs - `type: "module"`: - `.js` is parsed as esm - does not support loading JSON or Native Module by default - default for entry point without an extension is esm * `--entry-type=[mode]` - allows you set the type on entry point. * A new file extension `.cjs`. - this is specifically to support importing commonjs in the `module` mode. - this is only in the esm loader, the commonjs loader remains untouched, but the extension will work in the old loader if you use the full file path. * `--es-module-specifier-resolution=[type]` - options are `explicit` (default) and `node` - by default our loader will not allow for optional extensions in the import, the path for a module must include the extension if there is one - by default our loader will not allow for importing directories that have an index file - developers can use `--es-module-specifier-resolution=node` to enable the commonjs specifier resolution algorithm - This is not a “feature” but rather an implementation for experimentation. It is expected to change before the flag is removed * `--experimental-json-loader` - the only way to import json when `"type": "module"` - when enable all `import 'thing.json'` will go through the experimental loader independent of mode - based on whatwg/html#4315 * You can use `package.main` to set an entry point for a module - the file extensions used in main will be resolved based on the `type` of the module Refs: https://github.com/nodejs/modules/blob/master/doc/plan-for-new-modules-implementation.md Refs: https://github.com/GeoffreyBooth/node-import-file-specifier-resolution-proposal Refs: nodejs/modules#180 Refs: nodejs/ecmascript-modules#6 Refs: nodejs/ecmascript-modules#12 Refs: nodejs/ecmascript-modules#28 Refs: nodejs/modules#255 Refs: whatwg/html#4315 Refs: WICG/webcomponents#770 Co-authored-by: Myles Borins <MylesBorins@google.com> Co-authored-by: John-David Dalton <john.david.dalton@gmail.com> Co-authored-by: Evan Plaice <evanplaice@gmail.com> Co-authored-by: Geoffrey Booth <webmaster@geoffreybooth.com> Co-authored-by: Michaël Zasso <targos@protonmail.com> PR-URL: #26745 Reviewed-By: Gus Caplan <me@gus.host> Reviewed-By: Guy Bedford <guybedford@gmail.com> Reviewed-By: Ben Coe <bencoe@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>

MylesBorins mentioned this issue Feb 26, 2019

esm: add experimental .json support to loader nodejs/ecmascript-modules#43

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voxsoftware mentioned this issue Mar 3, 2019

A question about this proposals #284

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ljharb mentioned this issue Mar 15, 2019

Announcement blog post #291

Merged

MylesBorins closed this as completed Apr 10, 2019

hyf0 mentioned this issue Jun 26, 2024

incorrect bundle is generated when require(<json file>) is included rolldown/rolldown#1446

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JSON Modules #255

JSON Modules #255

MylesBorins commented Jan 22, 2019 •

edited

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MylesBorins commented Feb 26, 2019

JSON Modules #255

JSON Modules #255

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MylesBorins commented Jan 22, 2019 • edited Loading

MylesBorins commented Feb 26, 2019

MylesBorins commented Jan 22, 2019 •

edited

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