A package is a folder tree described by a package.json file. The package\nconsists of the folder containing the package.json file and all subfolders\nuntil the next folder containing another package.json file, or a folder\nnamed node_modules.
This page provides guidance for package authors writing package.json files\nalong with a reference for the package.json fields defined by Node.js.
Node.js will treat the following as ES modules when passed to node as the\ninitial input, or when referenced by import statements or import()\nexpressions:
Files with an .mjs extension.
Files with a .js extension when the nearest parent package.json file\ncontains a top-level \"type\" field with a value of \"module\".
Strings passed in as an argument to --eval, or piped to node via STDIN,\nwith the flag --input-type=module.
Code containing syntax only successfully parsed as ES modules, such as\nimport or export statements or import.meta, with no explicit marker of\nhow it should be interpreted. Explicit markers are .mjs or .cjs\nextensions, package.json \"type\" fields with either \"module\" or\n\"commonjs\" values, or the --input-type flag. Dynamic import()\nexpressions are supported in either CommonJS or ES modules and would not force\na file to be treated as an ES module. See Syntax detection.
Node.js will treat the following as CommonJS when passed to node as the\ninitial input, or when referenced by import statements or import()\nexpressions:
Files with a .cjs extension.
Files with a .js extension when the nearest parent package.json file\ncontains a top-level field \"type\" with a value of \"commonjs\".
Strings passed in as an argument to --eval or --print, or piped to node\nvia STDIN, with the flag --input-type=commonjs.
Files with a .js extension with no parent package.json file or where the\nnearest parent package.json file lacks a type field, and where the code\ncan evaluate successfully as CommonJS. In other words, Node.js tries to run\nsuch \"ambiguous\" files as CommonJS first, and will retry evaluating them as ES\nmodules if the evaluation as CommonJS fails because the parser found ES module\nsyntax.
Writing ES module syntax in \"ambiguous\" files incurs a performance cost, and\ntherefore it is encouraged that authors be explicit wherever possible. In\nparticular, package authors should always include the \"type\" field in\ntheir package.json files, even in packages where all sources are CommonJS.\nBeing explicit about the type of the package will future-proof the package in\ncase the default type of Node.js ever changes, and it will also make things\neasier for build tools and loaders to determine how the files in the package\nshould be interpreted.
Node.js will inspect the source code of ambiguous input to determine whether it\ncontains ES module syntax; if such syntax is detected, the input will be treated\nas an ES module.
\nAmbiguous input is defined as:
\n.js extension or no extension; and either no controlling\npackage.json file or one that lacks a type field.--eval or STDIN) when --input-typeis not specified.ES module syntax is defined as syntax that would throw when evaluated as\nCommonJS. This includes the following:
\nimport statements (but not import() expressions, which are valid in\nCommonJS).export statements.import.meta references.await at the top level of a module.require, module,\nexports, __dirname, __filename).Node.js has two systems for resolving a specifier and loading modules.
\nThere is the CommonJS module loader:
\nrequire() calls..js, .json, and finally .node) and then attempt to resolve\nfolders as modules..json as JSON text files..node files are interpreted as compiled addon modules loaded with\nprocess.dlopen()..json or .node extensions as JavaScript\ntext files.await).\nWhen used to load a JavaScript text file that is not an ECMAScript module,\nthe file will be loaded as a CommonJS module.There is the ECMAScript module loader:
\nrequire().import statements and import() expressions.'./startup/index.js') must be fully specified..js, .mjs, and .cjs extensions for JavaScript text\nfiles.cjs-module-lexer to try to identify named exports,\nwhich are available if they can be determined through static analysis.\nImported CommonJS modules have their URLs converted to absolute\npaths and are then loaded via the CommonJS module loader.Within a package, the package.json \"type\" field defines how\nNode.js should interpret .js files. If a package.json file does not have a\n\"type\" field, .js files are treated as CommonJS.
A package.json \"type\" value of \"module\" tells Node.js to interpret .js\nfiles within that package as using ES module syntax.
The \"type\" field applies not only to initial entry points (node my-app.js)\nbut also to files referenced by import statements and import() expressions.
// my-app.js, treated as an ES module because there is a package.json\n// file in the same folder with \"type\": \"module\".\n\nimport './startup/init.js';\n// Loaded as ES module since ./startup contains no package.json file,\n// and therefore inherits the \"type\" value from one level up.\n\nimport 'commonjs-package';\n// Loaded as CommonJS since ./node_modules/commonjs-package/package.json\n// lacks a \"type\" field or contains \"type\": \"commonjs\".\n\nimport './node_modules/commonjs-package/index.js';\n// Loaded as CommonJS since ./node_modules/commonjs-package/package.json\n// lacks a \"type\" field or contains \"type\": \"commonjs\".\nFiles ending with .mjs are always loaded as ES modules regardless of\nthe nearest parent package.json.
Files ending with .cjs are always loaded as CommonJS regardless of the\nnearest parent package.json.
import './legacy-file.cjs';\n// Loaded as CommonJS since .cjs is always loaded as CommonJS.\n\nimport 'commonjs-package/src/index.mjs';\n// Loaded as ES module since .mjs is always loaded as ES module.\nThe .mjs and .cjs extensions can be used to mix types within the same\npackage:
Within a \"type\": \"module\" package, Node.js can be instructed to\ninterpret a particular file as CommonJS by naming it with a .cjs\nextension (since both .js and .mjs files are treated as ES modules within\na \"module\" package).
Within a \"type\": \"commonjs\" package, Node.js can be instructed to\ninterpret a particular file as an ES module by naming it with an .mjs\nextension (since both .js and .cjs files are treated as CommonJS within a\n\"commonjs\" package).
Strings passed in as an argument to --eval (or -e), or piped to node via\nSTDIN, are treated as ES modules when the --input-type=module flag\nis set.
node --input-type=module --eval \"import { sep } from 'node:path'; console.log(sep);\"\n\necho \"import { sep } from 'node:path'; console.log(sep);\" | node --input-type=module\nFor completeness there is also --input-type=commonjs, for explicitly running\nstring input as CommonJS. This is the default behavior if --input-type is\nunspecified.
In a package's package.json file, two fields can define entry points for a\npackage: \"main\" and \"exports\". Both fields apply to both ES module\nand CommonJS module entry points.
The \"main\" field is supported in all versions of Node.js, but its\ncapabilities are limited: it only defines the main entry point of the package.
The \"exports\" provides a modern alternative to \"main\" allowing\nmultiple entry points to be defined, conditional entry resolution support\nbetween environments, and preventing any other entry points besides those\ndefined in \"exports\". This encapsulation allows module authors to\nclearly define the public interface for their package.
For new packages targeting the currently supported versions of Node.js, the\n\"exports\" field is recommended. For packages supporting Node.js 10 and\nbelow, the \"main\" field is required. If both \"exports\" and\n\"main\" are defined, the \"exports\" field takes precedence over\n\"main\" in supported versions of Node.js.
Conditional exports can be used within \"exports\" to define different\npackage entry points per environment, including whether the package is\nreferenced via require or via import. For more information about supporting\nboth CommonJS and ES modules in a single package please consult\nthe dual CommonJS/ES module packages section.
Existing packages introducing the \"exports\" field will prevent consumers\nof the package from using any entry points that are not defined, including the\npackage.json (e.g. require('your-package/package.json')). This will\nlikely be a breaking change.
To make the introduction of \"exports\" non-breaking, ensure that every\npreviously supported entry point is exported. It is best to explicitly specify\nentry points so that the package's public API is well-defined. For example,\na project that previously exported main, lib,\nfeature, and the package.json could use the following package.exports:
{\n \"name\": \"my-package\",\n \"exports\": {\n \".\": \"./lib/index.js\",\n \"./lib\": \"./lib/index.js\",\n \"./lib/index\": \"./lib/index.js\",\n \"./lib/index.js\": \"./lib/index.js\",\n \"./feature\": \"./feature/index.js\",\n \"./feature/index\": \"./feature/index.js\",\n \"./feature/index.js\": \"./feature/index.js\",\n \"./package.json\": \"./package.json\"\n }\n}\nAlternatively a project could choose to export entire folders both with and\nwithout extensioned subpaths using export patterns:
\n{\n \"name\": \"my-package\",\n \"exports\": {\n \".\": \"./lib/index.js\",\n \"./lib\": \"./lib/index.js\",\n \"./lib/*\": \"./lib/*.js\",\n \"./lib/*.js\": \"./lib/*.js\",\n \"./feature\": \"./feature/index.js\",\n \"./feature/*\": \"./feature/*.js\",\n \"./feature/*.js\": \"./feature/*.js\",\n \"./package.json\": \"./package.json\"\n }\n}\nWith the above providing backwards-compatibility for any minor package versions,\na future major change for the package can then properly restrict the exports\nto only the specific feature exports exposed:
\n{\n \"name\": \"my-package\",\n \"exports\": {\n \".\": \"./lib/index.js\",\n \"./feature/*.js\": \"./feature/*.js\",\n \"./feature/internal/*\": null\n }\n}\nWhen writing a new package, it is recommended to use the \"exports\" field:
{\n \"exports\": \"./index.js\"\n}\nWhen the \"exports\" field is defined, all subpaths of the package are\nencapsulated and no longer available to importers. For example,\nrequire('pkg/subpath.js') throws an ERR_PACKAGE_PATH_NOT_EXPORTED\nerror.
This encapsulation of exports provides more reliable guarantees\nabout package interfaces for tools and when handling semver upgrades for a\npackage. It is not a strong encapsulation since a direct require of any\nabsolute subpath of the package such as\nrequire('/path/to/node_modules/pkg/subpath.js') will still load subpath.js.
All currently supported versions of Node.js and modern build tools support the\n\"exports\" field. For projects using an older version of Node.js or a related\nbuild tool, compatibility can be achieved by including the \"main\" field\nalongside \"exports\" pointing to the same module:
{\n \"main\": \"./index.js\",\n \"exports\": \"./index.js\"\n}\nWhen using the \"exports\" field, custom subpaths can be defined along\nwith the main entry point by treating the main entry point as the\n\".\" subpath:
{\n \"exports\": {\n \".\": \"./index.js\",\n \"./submodule.js\": \"./src/submodule.js\"\n }\n}\nNow only the defined subpath in \"exports\" can be imported by a consumer:
import submodule from 'es-module-package/submodule.js';\n// Loads ./node_modules/es-module-package/src/submodule.js\nWhile other subpaths will error:
\nimport submodule from 'es-module-package/private-module.js';\n// Throws ERR_PACKAGE_PATH_NOT_EXPORTED\nPackage authors should provide either extensioned (import 'pkg/subpath.js') or\nextensionless (import 'pkg/subpath') subpaths in their exports. This ensures\nthat there is only one subpath for each exported module so that all dependents\nimport the same consistent specifier, keeping the package contract clear for\nconsumers and simplifying package subpath completions.
Traditionally, packages tended to use the extensionless style, which has the\nbenefits of readability and of masking the true path of the file within the\npackage.
\nWith import maps now providing a standard for package resolution in browsers\nand other JavaScript runtimes, using the extensionless style can result in\nbloated import map definitions. Explicit file extensions can avoid this issue by\nenabling the import map to utilize a packages folder mapping to map multiple\nsubpaths where possible instead of a separate map entry per package subpath\nexport. This also mirrors the requirement of using the full specifier path\nin relative and absolute import specifiers.
", "type": "module", "displayName": "Extensions in subpaths" } ], "type": "module", "displayName": "Subpath exports" }, { "textRaw": "Exports sugar", "name": "exports_sugar", "meta": { "added": [ "v12.11.0" ], "changes": [] }, "desc": "If the \".\" export is the only export, the \"exports\" field provides sugar\nfor this case being the direct \"exports\" field value.
{\n \"exports\": {\n \".\": \"./index.js\"\n }\n}\ncan be written:
\n{\n \"exports\": \"./index.js\"\n}\nIn addition to the \"exports\" field, there is a package \"imports\" field\nto create private mappings that only apply to import specifiers from within the\npackage itself.
Entries in the \"imports\" field must always start with # to ensure they are\ndisambiguated from external package specifiers.
For example, the imports field can be used to gain the benefits of conditional\nexports for internal modules:
\n// package.json\n{\n \"imports\": {\n \"#dep\": {\n \"node\": \"dep-node-native\",\n \"default\": \"./dep-polyfill.js\"\n }\n },\n \"dependencies\": {\n \"dep-node-native\": \"^1.0.0\"\n }\n}\nwhere import '#dep' does not get the resolution of the external package\ndep-node-native (including its exports in turn), and instead gets the local\nfile ./dep-polyfill.js relative to the package in other environments.
Unlike the \"exports\" field, the \"imports\" field permits mapping to external\npackages.
The resolution rules for the imports field are otherwise analogous to the\nexports field.
", "type": "module", "displayName": "Subpath imports" }, { "textRaw": "Subpath patterns", "name": "subpath_patterns", "meta": { "added": [ "v14.13.0", "v12.20.0" ], "changes": [ { "version": [ "v16.10.0", "v14.19.0" ], "pr-url": "https://github.com/nodejs/node/pull/40041", "description": "Support pattern trailers in \"imports\" field." }, { "version": [ "v16.9.0", "v14.19.0" ], "pr-url": "https://github.com/nodejs/node/pull/39635", "description": "Support pattern trailers." } ] }, "desc": "For packages with a small number of exports or imports, we recommend\nexplicitly listing each exports subpath entry. But for packages that have\nlarge numbers of subpaths, this might cause package.json bloat and\nmaintenance issues.
For these use cases, subpath export patterns can be used instead:
\n// ./node_modules/es-module-package/package.json\n{\n \"exports\": {\n \"./features/*.js\": \"./src/features/*.js\"\n },\n \"imports\": {\n \"#internal/*.js\": \"./src/internal/*.js\"\n }\n}\n* maps expose nested subpaths as it is a string replacement syntax\nonly.
All instances of * on the right hand side will then be replaced with this\nvalue, including if it contains any / separators.
import featureX from 'es-module-package/features/x.js';\n// Loads ./node_modules/es-module-package/src/features/x.js\n\nimport featureY from 'es-module-package/features/y/y.js';\n// Loads ./node_modules/es-module-package/src/features/y/y.js\n\nimport internalZ from '#internal/z.js';\n// Loads ./node_modules/es-module-package/src/internal/z.js\nThis is a direct static matching and replacement without any special handling\nfor file extensions. Including the \"*.js\" on both sides of the mapping\nrestricts the exposed package exports to only JS files.
The property of exports being statically enumerable is maintained with exports\npatterns since the individual exports for a package can be determined by\ntreating the right hand side target pattern as a ** glob against the list of\nfiles within the package. Because node_modules paths are forbidden in exports\ntargets, this expansion is dependent on only the files of the package itself.
To exclude private subfolders from patterns, null targets can be used:
// ./node_modules/es-module-package/package.json\n{\n \"exports\": {\n \"./features/*.js\": \"./src/features/*.js\",\n \"./features/private-internal/*\": null\n }\n}\nimport featureInternal from 'es-module-package/features/private-internal/m.js';\n// Throws: ERR_PACKAGE_PATH_NOT_EXPORTED\n\nimport featureX from 'es-module-package/features/x.js';\n// Loads ./node_modules/es-module-package/src/features/x.js\nConditional exports provide a way to map to different paths depending on\ncertain conditions. They are supported for both CommonJS and ES module imports.
\nFor example, a package that wants to provide different ES module exports for\nrequire() and import can be written:
// package.json\n{\n \"exports\": {\n \"import\": \"./index-module.js\",\n \"require\": \"./index-require.cjs\"\n },\n \"type\": \"module\"\n}\nNode.js implements the following conditions, listed in order from most\nspecific to least specific as conditions should be defined:
\n\"node-addons\" - similar to \"node\" and matches for any Node.js environment.\nThis condition can be used to provide an entry point which uses native C++\naddons as opposed to an entry point which is more universal and doesn't rely\non native addons. This condition can be disabled via the\n--no-addons flag.\"node\" - matches for any Node.js environment. Can be a CommonJS or ES\nmodule file. In most cases explicitly calling out the Node.js platform is\nnot necessary.\"import\" - matches when the package is loaded via import or\nimport(), or via any top-level import or resolve operation by the\nECMAScript module loader. Applies regardless of the module format of the\ntarget file. Always mutually exclusive with \"require\".\"require\" - matches when the package is loaded via require(). The\nreferenced file should be loadable with require() although the condition\nmatches regardless of the module format of the target file. Expected\nformats include CommonJS, JSON, native addons, and ES modules. Always mutually\nexclusive with \"import\".\"module-sync\" - matches no matter the package is loaded via import,\nimport() or require(). The format is expected to be ES modules that does\nnot contain top-level await in its module graph - if it does,\nERR_REQUIRE_ASYNC_MODULE will be thrown when the module is require()-ed.\"default\" - the generic fallback that always matches. Can be a CommonJS\nor ES module file. This condition should always come last.Within the \"exports\" object, key order is significant. During condition\nmatching, earlier entries have higher priority and take precedence over later\nentries. The general rule is that conditions should be from most specific to\nleast specific in object order.
Using the \"import\" and \"require\" conditions can lead to some hazards,\nwhich are further explained in the dual CommonJS/ES module packages section.
The \"node-addons\" condition can be used to provide an entry point which\nuses native C++ addons. However, this condition can be disabled via the\n--no-addons flag. When using \"node-addons\", it's recommended to treat\n\"default\" as an enhancement that provides a more universal entry point, e.g.\nusing WebAssembly instead of a native addon.
Conditional exports can also be extended to exports subpaths, for example:
\n{\n \"exports\": {\n \".\": \"./index.js\",\n \"./feature.js\": {\n \"node\": \"./feature-node.js\",\n \"default\": \"./feature.js\"\n }\n }\n}\nDefines a package where require('pkg/feature.js') and\nimport 'pkg/feature.js' could provide different implementations between\nNode.js and other JS environments.
When using environment branches, always include a \"default\" condition where\npossible. Providing a \"default\" condition ensures that any unknown JS\nenvironments are able to use this universal implementation, which helps avoid\nthese JS environments from having to pretend to be existing environments in\norder to support packages with conditional exports. For this reason, using\n\"node\" and \"default\" condition branches is usually preferable to using\n\"node\" and \"browser\" condition branches.
In addition to direct mappings, Node.js also supports nested condition objects.
\nFor example, to define a package that only has dual mode entry points for\nuse in Node.js but not the browser:
\n{\n \"exports\": {\n \"node\": {\n \"import\": \"./feature-node.mjs\",\n \"require\": \"./feature-node.cjs\"\n },\n \"default\": \"./feature.mjs\"\n }\n}\nConditions continue to be matched in order as with flat conditions. If\na nested condition does not have any mapping it will continue checking\nthe remaining conditions of the parent condition. In this way nested\nconditions behave analogously to nested JavaScript if statements.
When running Node.js, custom user conditions can be added with the\n--conditions flag:
node --conditions=development index.js\nwhich would then resolve the \"development\" condition in package imports and\nexports, while resolving the existing \"node\", \"node-addons\", \"default\",\n\"import\", and \"require\" conditions as appropriate.
Any number of custom conditions can be set with repeat flags.
\nTypical conditions should only contain alphanumerical characters,\nusing \":\", \"-\", or \"=\" as separators if necessary. Anything else may run\ninto compability issues outside of node.
\nIn node, conditions have very few restrictions, but specifically these include:
\nCondition strings other than the \"import\", \"require\", \"node\", \"module-sync\",\n\"node-addons\" and \"default\" conditions\nimplemented in Node.js core are ignored by default.
Other platforms may implement other conditions and user conditions can be\nenabled in Node.js via the --conditions / -C flag.
Since custom package conditions require clear definitions to ensure correct\nusage, a list of common known package conditions and their strict definitions\nis provided below to assist with ecosystem coordination.
\n\"types\" - can be used by typing systems to resolve the typing file for\nthe given export. This condition should always be included first.\"browser\" - any web browser environment.\"development\" - can be used to define a development-only environment\nentry point, for example to provide additional debugging context such as\nbetter error messages when running in a development mode. Must always be\nmutually exclusive with \"production\".\"production\" - can be used to define a production environment entry\npoint. Must always be mutually exclusive with \"development\".For other runtimes, platform-specific condition key definitions are maintained\nby the WinterCG in the Runtime Keys proposal specification.
\nNew conditions definitions may be added to this list by creating a pull request\nto the Node.js documentation for this section. The requirements for listing\na new condition definition here are that:
\n\"types\" condition is a good example: It\ndoesn't really belong in the Runtime Keys proposal but is a good fit\nhere in the Node.js docs.The above definitions may be moved to a dedicated conditions registry in due\ncourse.
", "type": "module", "displayName": "Community Conditions Definitions" }, { "textRaw": "Self-referencing a package using its name", "name": "self-referencing_a_package_using_its_name", "meta": { "added": [ "v13.1.0", "v12.16.0" ], "changes": [ { "version": [ "v13.6.0", "v12.16.0" ], "pr-url": "https://github.com/nodejs/node/pull/31002", "description": "Unflag self-referencing a package using its name." } ] }, "desc": "Within a package, the values defined in the package's\npackage.json \"exports\" field can be referenced via the package's name.\nFor example, assuming the package.json is:
// package.json\n{\n \"name\": \"a-package\",\n \"exports\": {\n \".\": \"./index.mjs\",\n \"./foo.js\": \"./foo.js\"\n }\n}\nThen any module in that package can reference an export in the package itself:
\n// ./a-module.mjs\nimport { something } from 'a-package'; // Imports \"something\" from ./index.mjs.\nSelf-referencing is available only if package.json has \"exports\", and\nwill allow importing only what that \"exports\" (in the package.json)\nallows. So the code below, given the previous package, will generate a runtime\nerror:
// ./another-module.mjs\n\n// Imports \"another\" from ./m.mjs. Fails because\n// the \"package.json\" \"exports\" field\n// does not provide an export named \"./m.mjs\".\nimport { another } from 'a-package/m.mjs';\nSelf-referencing is also available when using require, both in an ES module,\nand in a CommonJS one. For example, this code will also work:
// ./a-module.js\nconst { something } = require('a-package/foo.js'); // Loads from ./foo.js.\nFinally, self-referencing also works with scoped packages. For example, this\ncode will also work:
\n// package.json\n{\n \"name\": \"@my/package\",\n \"exports\": \"./index.js\"\n}\n// ./index.js\nmodule.exports = 42;\n// ./other.js\nconsole.log(require('@my/package'));\n$ node other.js\n42\nSee the package examples repository for details.
", "type": "misc", "displayName": "Dual CommonJS/ES module packages" }, { "textRaw": "Node.js `package.json` field definitions", "name": "node.js_`package.json`_field_definitions", "desc": "This section describes the fields used by the Node.js runtime. Other tools (such\nas npm) use\nadditional fields which are ignored by Node.js and not documented here.
\nThe following fields in package.json files are used in Node.js:
\"name\" - Relevant when using named imports within a package. Also used\nby package managers as the name of the package.\"main\" - The default module when loading the package, if exports is not\nspecified, and in versions of Node.js prior to the introduction of exports.\"type\" - The package type determining whether to load .js files as\nCommonJS or ES modules.\"exports\" - Package exports and conditional exports. When present,\nlimits which submodules can be loaded from within the package.\"imports\" - Package imports, for use by modules within the package\nitself.{\n \"name\": \"package-name\"\n}\nThe \"name\" field defines your package's name. Publishing to the\nnpm registry requires a name that satisfies\ncertain requirements.
The \"name\" field can be used in addition to the \"exports\" field to\nself-reference a package using its name.
{\n \"main\": \"./index.js\"\n}\nThe \"main\" field defines the entry point of a package when imported by name\nvia a node_modules lookup. Its value is a path.
When a package has an \"exports\" field, this will take precedence over the\n\"main\" field when importing the package by name.
It also defines the script that is used when the package directory is loaded\nvia require().
// This resolves to ./path/to/directory/index.js.\nrequire('./path/to/directory');\nThe \"type\" field defines the module format that Node.js uses for all\n.js files that have that package.json file as their nearest parent.
Files ending with .js are loaded as ES modules when the nearest parent\npackage.json file contains a top-level field \"type\" with a value of\n\"module\".
The nearest parent package.json is defined as the first package.json found\nwhen searching in the current folder, that folder's parent, and so on up\nuntil a node_modules folder or the volume root is reached.
// package.json\n{\n \"type\": \"module\"\n}\n# In same folder as preceding package.json\nnode my-app.js # Runs as ES module\nIf the nearest parent package.json lacks a \"type\" field, or contains\n\"type\": \"commonjs\", .js files are treated as CommonJS. If the volume\nroot is reached and no package.json is found, .js files are treated as\nCommonJS.
import statements of .js files are treated as ES modules if the nearest\nparent package.json contains \"type\": \"module\".
// my-app.js, part of the same example as above\nimport './startup.js'; // Loaded as ES module because of package.json\nRegardless of the value of the \"type\" field, .mjs files are always treated\nas ES modules and .cjs files are always treated as CommonJS.
{\n \"exports\": \"./index.js\"\n}\nThe \"exports\" field allows defining the entry points of a package when\nimported by name loaded either via a node_modules lookup or a\nself-reference to its own name. It is supported in Node.js 12+ as an\nalternative to the \"main\" that can support defining subpath exports\nand conditional exports while encapsulating internal unexported modules.
Conditional Exports can also be used within \"exports\" to define different\npackage entry points per environment, including whether the package is\nreferenced via require or via import.
All paths defined in the \"exports\" must be relative file URLs starting with\n./.
// package.json\n{\n \"imports\": {\n \"#dep\": {\n \"node\": \"dep-node-native\",\n \"default\": \"./dep-polyfill.js\"\n }\n },\n \"dependencies\": {\n \"dep-node-native\": \"^1.0.0\"\n }\n}\nEntries in the imports field must be strings starting with #.
Package imports permit mapping to external packages.
\nThis field defines subpath imports for the current package.
", "type": "module", "displayName": "`\"imports\"`" } ], "type": "misc", "displayName": "Node.js `package.json` field definitions" } ] } ] }