v0.16.7

• Include file loader strings in metafile imports (#2731)

  Bundling a file with the file loader copies that file to the output directory and imports a module with the path to the copied file in the default export. Previously when bundling with the file loader, there was no reference in the metafile from the JavaScript file containing the path string to the copied file. With this release, there will now be a reference in the metafile in the imports array with the kind file-loader:

   {
     ...
     "outputs": {
       "out/image-55CCFTCE.svg": {
         ...
       },
       "out/entry.js": {
         "imports": [
  +        {
  +          "path": "out/image-55CCFTCE.svg",
  +          "kind": "file-loader"
  +        }
         ],
         ...
       }
     }
   }

• Fix byte counts in metafile regarding references to other output files (#2071)

  Previously files that contained references to other output files had slightly incorrect metadata for the byte counts of input files which contributed to that output file. So for example if app.js imports image.png using the file loader and esbuild generates out.js and image-LSAMBFUD.png, the metadata for how many bytes of out.js are from app.js was slightly off (the metadata for the byte count of out.js was still correct). The reason is because esbuild substitutes the final paths for references between output files toward the end of the build to handle cyclic references, and the byte counts needed to be adjusted as well during the path substitution. This release fixes these byte counts (specifically the bytesInOutput values).

• The alias feature now strips a trailing slash (#2730)

  People sometimes add a trailing slash to the name of one of node's built-in modules to force node to import from the file system instead of importing the built-in module. For example, importing util imports node's built-in module called util but importing util/ tries to find a package called util on the file system. Previously attempting to use esbuild's package alias feature to replace imports to util with a specific file would fail because the file path would also gain a trailing slash (e.g. mapping util to ./file.js turned util/ into ./file.js/). With this release, esbuild will now omit the path suffix if it's a single trailing slash, which should now allow you to successfully apply aliases to these import paths.

v0.16.6

• Do not mark subpath imports as external with --packages=external (#2741)

  Node has a feature called subpath imports where special import paths that start with # are resolved using the imports field in the package.json file of the enclosing package. The intent of the newly-added --packages=external setting is to exclude a package's dependencies from the bundle. Since a package's subpath imports are only accessible within that package, it's wrong for them to be affected by --packages=external. This release changes esbuild so that --packages=external no longer affects subpath imports.

• Forbid invalid numbers in JSON files

  Previously esbuild parsed numbers in JSON files using the same syntax as JavaScript. But starting from this release, esbuild will now parse them with JSON syntax instead. This means the following numbers are no longer allowed by esbuild in JSON files:

  • Legacy octal literals (non-zero integers starting with 0)
  • The 0b, 0o, and 0x numeric prefixes
  • Numbers containing _ such as 1_000
  • Leading and trailing . such as 0. and .0
  • Numbers with a space after the - such as - 1

• Add external imports to metafile (#905, #1768, #1933, #1939)

  External imports now appear in imports arrays in the metafile (which is present when bundling with metafile: true) next to normal imports, but additionally have external: true to set them apart. This applies both to files in the inputs section and the outputs section. Here's an example:

   {
     "inputs": {
       "style.css": {
         "bytes": 83,
         "imports": [
  +        {
  +          "path": "https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css",
  +          "kind": "import-rule",
  +          "external": true
  +        }
         ]
       },
       "app.js": {
         "bytes": 100,
         "imports": [
  +        {
  +          "path": "https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js",
  +          "kind": "import-statement",
  +          "external": true
  +        },
           {
             "path": "style.css",
             "kind": "import-statement"
           }
         ]
       }
     },
     "outputs": {
       "out/app.js": {
         "imports": [
  +        {
  +          "path": "https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.min.js",
  +          "kind": "require-call",
  +          "external": true
  +        }
         ],
         "exports": [],
         "entryPoint": "app.js",
         "cssBundle": "out/app.css",
         "inputs": {
           "app.js": {
             "bytesInOutput": 113
           },
           "style.css": {
             "bytesInOutput": 0
           }
         },
         "bytes": 528
       },
       "out/app.css": {
         "imports": [
  +        {
  +          "path": "https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css",
  +          "kind": "import-rule",
  +          "external": true
  +        }
         ],
         "inputs": {
           "style.css": {
             "bytesInOutput": 0
           }
         },
         "bytes": 100
       }
     }
   }

  One additional useful consequence of this is that the imports array is now populated when bundling is disabled. So you can now use esbuild with bundling disabled to inspect a file's imports.

v0.16.5

• Make it easy to exclude all packages from a bundle (#1958, #1975, #2164, #2246, #2542)

  When bundling for node, it's often necessary to exclude npm packages from the bundle since they weren't designed with esbuild bundling in mind and don't work correctly after being bundled. For example, they may use __dirname and run-time file system calls to load files, which doesn't work after bundling with esbuild. Or they may compile a native .node extension that has similar expectations about the layout of the file system that are no longer true after bundling (even if the .node extension is copied next to the bundle).

  The way to get this to work with esbuild is to use the --external: flag. For example, the fsevents package contains a native .node extension and shouldn't be bundled. To bundle code that uses it, you can pass --external:fsevents to esbuild to exclude it from your bundle. You will then need to ensure that the fsevents package is still present when you run your bundle (e.g. by publishing your bundle to npm as a package with a dependency on fsevents).

  It was possible to automatically do this for all of your dependencies, but it was inconvenient. You had to write some code that read your package.json file and passed the keys of the dependencies, devDependencies, peerDependencies, and/or optionalDependencies maps to esbuild as external packages (either that or write a plugin to mark all package paths as external). Previously esbuild's recommendation for making this easier was to do --external:./node_modules/* (added in version 0.14.13). However, this was a bad idea because it caused compatibility problems with many node packages as it caused esbuild to mark the post-resolve path as external instead of the pre-resolve path. Doing that could break packages that are published as both CommonJS and ESM if esbuild's bundler is also used to do a module format conversion.

  With this release, you can now do the following to automatically exclude all packages from your bundle:

  • CLI:

    esbuild --bundle --packages=external
    

  • JS:

    esbuild.build({
      bundle: true,
      packages: 'external',
    })

  • Go:

    api.Build(api.BuildOptions{
      Bundle:   true,
      Packages: api.PackagesExternal,
    })

  Doing --external:./node_modules/* is still possible and still has the same behavior, but is no longer recommended. I recommend that you use the new packages feature instead.

• Fix some subtle bugs with tagged template literals

  This release fixes a bug where minification could incorrectly change the value of this within tagged template literal function calls:

  // Original code
  function f(x) {
    let z = y.z
    return z``
  }
  
  // Old output (with --minify)
  function f(n){return y.z``}
  
  // New output (with --minify)
  function f(n){return(0,y.z)``}

  This release also fixes a bug where using optional chaining with --target=es2019 or earlier could incorrectly change the value of this within tagged template literal function calls:

  // Original code
  var obj = {
    foo: function() {
      console.log(this === obj);
    }
  };
  (obj?.foo)``;
  
  // Old output (with --target=es6)
  var obj = {
    foo: function() {
      console.log(this === obj);
    }
  };
  (obj == null ? void 0 : obj.foo)``;
  
  // New output (with --target=es6)
  var __freeze = Object.freeze;
  var __defProp = Object.defineProperty;
  var __template = (cooked, raw) => __freeze(__defProp(cooked, "raw", { value: __freeze(raw || cooked.slice()) }));
  var _a;
  var obj = {
    foo: function() {
      console.log(this === obj);
    }
  };
  (obj == null ? void 0 : obj.foo).call(obj, _a || (_a = __template([""])));

• Some slight minification improvements

  The following minification improvements were implemented:

  • if (~a !== 0) throw x; => if (~a) throw x;
  • if ((a | b) !== 0) throw x; => if (a | b) throw x;
  • if ((a & b) !== 0) throw x; => if (a & b) throw x;
  • if ((a ^ b) !== 0) throw x; => if (a ^ b) throw x;
  • if ((a << b) !== 0) throw x; => if (a << b) throw x;
  • if ((a >> b) !== 0) throw x; => if (a >> b) throw x;
  • if ((a >>> b) !== 0) throw x; => if (a >>> b) throw x;
  • if (!!a || !!b) throw x; => if (a || b) throw x;
  • if (!!a && !!b) throw x; => if (a && b) throw x;
  • if (a ? !!b : !!c) throw x; => if (a ? b : c) throw x;

v0.16.4

• Fix binary downloads from the @esbuild/ scope for Deno (#2729)

  Version 0.16.0 of esbuild moved esbuild's binary executables into npm packages under the @esbuild/ scope, which accidentally broke the binary downloader script for Deno. This release fixes this script so it should now be possible to use esbuild version 0.16.4+ with Deno.

v0.16.3

• Fix a hang with the JS API in certain cases (#2727)

  A change that was made in version 0.15.13 accidentally introduced a case when using esbuild's JS API could cause the node process to fail to exit. The change broke esbuild's watchdog timer, which detects if the parent process no longer exists and then automatically exits esbuild. This hang happened when you ran node as a child process with the stderr stream set to pipe instead of inherit, in the child process you call esbuild's JS API and pass incremental: true but do not call dispose() on the returned rebuild object, and then call process.exit(). In that case the parent node process was still waiting for the esbuild process that was created by the child node process to exit. The change made in version 0.15.13 was trying to avoid using Go's sync.WaitGroup API incorrectly because the API is not thread-safe. Instead of doing this, I have now reverted that change and implemented a thread-safe version of the sync.WaitGroup API for esbuild to use instead.

v0.16.2

• Fix process.env.NODE_ENV substitution when transforming (#2718)

  Version 0.16.0 introduced an unintentional regression that caused process.env.NODE_ENV to be automatically substituted with either "development" or "production" when using esbuild's transform API. This substitution is a necessary feature of esbuild's build API because the React framework crashes when you bundle it without doing this. But the transform API is typically used as part of a larger build pipeline so the benefit of esbuild doing this automatically is not as clear, and esbuild previously didn't do this.

  However, version 0.16.0 switched the default value of the platform setting for the transform API from neutral to browser, both to align it with esbuild's documentation (which says browser is the default value) and because escaping the </script> character sequence is now tied to the browser platform (see the release notes for version 0.16.0 for details). That accidentally enabled automatic substitution of process.env.NODE_ENV because esbuild always did that for code meant for the browser. To fix this regression, esbuild will now only automatically substitute process.env.NODE_ENV when using the build API.

• Prevent define from substituting constants into assignment position (#2719)

  The define feature lets you replace certain expressions with constants. For example, you could use it to replace references to the global property reference window.DEBUG with false at compile time, which can then potentially help esbuild remove unused code from your bundle. It's similar to DefinePlugin in Webpack.

  However, if you write code such as window.DEBUG = true and then defined window.DEBUG to false, esbuild previously generated the output false = true which is a syntax error in JavaScript. This behavior is not typically a problem because it doesn't make sense to substitute window.DEBUG with a constant if its value changes at run-time (Webpack's DefinePlugin also generates false = true in this case). But it can be alarming to have esbuild generate code with a syntax error.

  So with this release, esbuild will no longer substitute define constants into assignment position to avoid generating code with a syntax error. Instead esbuild will generate a warning, which currently looks like this:

  ▲ [WARNING] Suspicious assignment to defined constant "window.DEBUG" [assign-to-define]
  
      example.js:1:0:
        1 │ window.DEBUG = true
          ╵ ~~~~~~~~~~~~
  
    The expression "window.DEBUG" has been configured to be replaced with a constant using the
    "define" feature. If this expression is supposed to be a compile-time constant, then it doesn't
    make sense to assign to it here. Or if this expression is supposed to change at run-time, this
    "define" substitution should be removed.
  

• Fix a regression with npm install --no-optional (#2720)

  Normally when you install esbuild with npm install, npm itself is the tool that downloads the correct binary executable for the current platform. This happens because of how esbuild's primary package uses npm's optionalDependencies feature. However, if you deliberately disable this with npm install --no-optional then esbuild's install script will attempt to repair the installation by manually downloading and extracting the binary executable from the package that was supposed to be installed.

  The change in version 0.16.0 to move esbuild's nested packages into the @esbuild/ scope unintentionally broke this logic because of how npm's URL structure is different for scoped packages vs. normal packages. It was actually already broken for a few platforms earlier because esbuild already had packages for some platforms in the @esbuild/ scope, but I didn't discover this then because esbuild's integration tests aren't run on all platforms. Anyway, this release contains some changes to the install script that should hopefully get this scenario working again.

v0.16.1

This is a hotfix for the previous release.

• Re-allow importing JSON with the copy loader using an import assertion

  The previous release made it so when assert { type: 'json' } is present on an import statement, esbuild validated that the json loader was used. This is what an import assertion is supposed to do. However, I forgot about the relatively new copy loader, which sort of behaves as if the import path was marked as external (and thus not loaded at all) except that the file is copied to the output directory and the import path is rewritten to point to the copy. In this case whatever JavaScript runtime ends up running the code is the one to evaluate the import assertion. So esbuild should really allow this case as well. With this release, esbuild now allows both the json and copy loaders when an assert { type: 'json' } import assertion is present.

v0.16.0

This release deliberately contains backwards-incompatible changes. To avoid automatically picking up releases like this, you should either be pinning the exact version of esbuild in your package.json file (recommended) or be using a version range syntax that only accepts patch upgrades such as ^0.15.0 or ~0.15.0. See npm's documentation about semver for more information.

• Move all binary executable packages to the @esbuild/ scope

  Binary package executables for esbuild are published as individual packages separate from the main esbuild package so you only have to download the relevant one for the current platform when you install esbuild. This release moves all of these packages under the @esbuild/ scope to avoid collisions with 3rd-party packages. It also changes them to a consistent naming scheme that uses the os and cpu names from node.

  The package name changes are as follows:

  • @esbuild/linux-loong64 => @esbuild/linux-loong64 (no change)
  • esbuild-android-64 => @esbuild/android-x64
  • esbuild-android-arm64 => @esbuild/android-arm64
  • esbuild-darwin-64 => @esbuild/darwin-x64
  • esbuild-darwin-arm64 => @esbuild/darwin-arm64
  • esbuild-freebsd-64 => @esbuild/freebsd-x64
  • esbuild-freebsd-arm64 => @esbuild/freebsd-arm64
  • esbuild-linux-32 => @esbuild/linux-ia32
  • esbuild-linux-64 => @esbuild/linux-x64
  • esbuild-linux-arm => @esbuild/linux-arm
  • esbuild-linux-arm64 => @esbuild/linux-arm64
  • esbuild-linux-mips64le => @esbuild/linux-mips64el
  • esbuild-linux-ppc64le => @esbuild/linux-ppc64
  • esbuild-linux-riscv64 => @esbuild/linux-riscv64
  • esbuild-linux-s390x => @esbuild/linux-s390x
  • esbuild-netbsd-64 => @esbuild/netbsd-x64
  • esbuild-openbsd-64 => @esbuild/openbsd-x64
  • esbuild-sunos-64 => @esbuild/sunos-x64
  • esbuild-wasm => esbuild-wasm (no change)
  • esbuild-windows-32 => @esbuild/win32-ia32
  • esbuild-windows-64 => @esbuild/win32-x64
  • esbuild-windows-arm64 => @esbuild/win32-arm64
  • esbuild => esbuild (no change)

  Normal usage of the esbuild and esbuild-wasm packages should not be affected. These name changes should only affect tools that hard-coded the individual binary executable package names into custom esbuild downloader scripts.

  This change was not made with performance in mind. But as a bonus, installing esbuild with npm may potentially happen faster now. This is because npm's package installation protocol is inefficient: it always downloads metadata for all past versions of each package even when it only needs metadata about a single version. This makes npm package downloads O(n) in the number of published versions, which penalizes packages like esbuild that are updated regularly. Since most of esbuild's package names have now changed, npm will now need to download much less data when installing esbuild (8.72mb of package manifests before this change → 0.06mb of package manifests after this change). However, this is only a temporary improvement. Installing esbuild will gradually get slower again as further versions of esbuild are published.

• Publish a shell script that downloads esbuild directly

  In addition to all of the existing ways to install esbuild, you can now also download esbuild directly like this:

  curl -fsSL https://esbuild.github.io/dl/latest | sh

  This runs a small shell script that downloads the latest esbuild binary executable to the current directory. This can be convenient on systems that don't have npm installed or when you just want to get a copy of esbuild quickly without any extra steps. If you want a specific version of esbuild (starting with this version onward), you can provide that version in the URL instead of latest:

  curl -fsSL https://esbuild.github.io/dl/v0.16.0 | sh

  Note that the download script needs to be able to access registry.npmjs.org to be able to complete the download. This download script doesn't yet support all of the platforms that esbuild supports because I lack the necessary testing environments. If the download script doesn't work for you because you're on an unsupported platform, please file an issue on the esbuild repo so we can add support for it.

• Fix some parameter names for the Go API

  This release changes some parameter names for the Go API to be consistent with the JavaScript and CLI APIs:

  • OutExtensions => OutExtension
  • JSXMode => JSX

• Add additional validation of API parameters

  The JavaScript API now does some additional validation of API parameters to catch incorrect uses of esbuild's API. The biggest impact of this is likely that esbuild now strictly only accepts strings with the define parameter. This would already have been a type error with esbuild's TypeScript type definitions, but it was previously not enforced for people using esbuild's API JavaScript without TypeScript.

  The define parameter appears at first glance to take a JSON object if you aren't paying close attention, but this actually isn't true. Values for define are instead strings of JavaScript code. This means you have to use define: { foo: '"bar"' } to replace foo with the string "bar". Using define: { foo: 'bar' } actually replaces foo with the identifier bar. Previously esbuild allowed you to pass define: { foo: false } and false was automatically converted into a string, which made it more confusing to understand what define actually represents. Starting with this release, passing non-string values such as with define: { foo: false } will no longer be allowed. You will now have to write define: { foo: 'false' } instead.

• Generate shorter data URLs if possible (#1843)

  Loading a file with esbuild's dataurl loader generates a JavaScript module with a data URL for that file in a string as a single default export. Previously the data URLs generated by esbuild all used base64 encoding. However, this is unnecessarily long for most textual data (e.g. SVG images). So with this release, esbuild's dataurl loader will now use percent encoding instead of base64 encoding if the result will be shorter. This can result in ~25% smaller data URLs for large SVGs. If you want the old behavior, you can use the base64 loader instead and then construct the data URL yourself.

• Avoid marking entry points as external (#2382)

  Previously you couldn't specify --external:* to mark all import paths as external because that also ended up making the entry point itself external, which caused the build to fail. With this release, esbuild's external API parameter no longer applies to entry points so using --external:* is now possible.

  One additional consequence of this change is that the kind parameter is now required when calling the resolve() function in esbuild's plugin API. Previously the kind parameter defaulted to entry-point, but that no longer interacts with external so it didn't seem wise for this to continue to be the default. You now have to specify kind so that the path resolution mode is explicit.

• Disallow non-default imports when assert { type: 'json' } is present

  There is now standard behavior for importing a JSON file into an ES module using an import statement. However, it requires you to place the assert { type: 'json' } import assertion after the import path. This import assertion tells the JavaScript runtime to throw an error if the import does not end up resolving to a JSON file. On the web, the type of a file is determined by the Content-Type HTTP header instead of by the file extension. The import assertion prevents security problems on the web where a .json file may actually resolve to a JavaScript file containing malicious code, which is likely not expected for an import that is supposed to only contain pure side-effect free data.

  By default, esbuild uses the file extension to determine the type of a file, so this import assertion is unnecessary with esbuild. However, esbuild's JSON import feature has a non-standard extension that allows you to import top-level properties of the JSON object as named imports. For example, esbuild lets you do this:

  import { version } from './package.json'

  This is useful for tree-shaking when bundling because it means esbuild will only include the the version field of package.json in your bundle. This is non-standard behavior though and doesn't match the behavior of what happens when you import JSON in a real JavaScript runtime (after adding assert { type: 'json' }). In a real JavaScript runtime the only thing you can import is the default import. So with this release, esbuild will now prevent you from importing non-default import names if assert { type: 'json' } is present. This ensures that code containing assert { type: 'json' } isn't relying on non-standard behavior that won't work everywhere. So the following code is now an error with esbuild when bundling:

  import { version } from './package.json' assert { type: 'json' }

  In addition, adding assert { type: 'json' } to an import statement now means esbuild will generate an error if the loader for the file is anything other than json, which is required by the import assertion specification.

• Provide a way to disable automatic escaping of </script> (#2649)

  If you inject esbuild's output into a script ...

v0.15.18

• Performance improvements for both JS and CSS

  This release brings noticeable performance improvements for JS parsing and for CSS parsing and printing. Here's an example benchmark for using esbuild to pretty-print a single large minified CSS file and JS file:

  Test case	Previous release	This release
  4.8mb CSS file	19ms	11ms (1.7x faster)
  5.8mb JS file	36ms	32ms (1.1x faster)

  The performance improvements were very straightforward:

  • Identifiers were being scanned using a generic character advancement function instead of using custom inline code. Advancing past each character involved UTF-8 decoding as well as updating multiple member variables. This was sped up using loop that skips UTF-8 decoding entirely and that only updates member variables once at the end. This is faster because identifiers are plain ASCII in the vast majority of cases, so Unicode decoding is almost always unnecessary.

  • CSS identifiers and CSS strings were still being printed one character at a time. Apparently I forgot to move this part of esbuild's CSS infrastructure beyond the proof-of-concept stage. These were both very obvious in the profiler, so I think maybe I have just never profiled esbuild's CSS printing before?

  • There was unnecessary work being done that was related to source maps when source map output was disabled. I likely haven't observed this before because esbuild's benchmarks always have source maps enabled. This work is now disabled when it's not going to be used.

  I definitely should have caught these performance issues earlier. Better late than never I suppose.

v0.15.17

• Search for missing source map code on the file system (#2711)

  Source maps are JSON files that map from compiled code back to the original code. They provide the original source code using two arrays: sources (required) and sourcesContent (optional). When bundling is enabled, esbuild is able to bundle code with source maps that was compiled by other tools (e.g. with Webpack) and emit source maps that map all the way back to the original code (e.g. before Webpack compiled it).

  Previously if the input source maps omitted the optional sourcesContent array, esbuild would use null for the source content in the source map that it generates (since the source content isn't available). However, sometimes the original source code is actually still present on the file system. With this release, esbuild will now try to find the original source code using the path in the sources array and will use that instead of null if it was found.

• Fix parsing bug with TypeScript infer and extends (#2712)

  This release fixes a bug where esbuild incorrectly failed to parse valid TypeScript code that nests extends inside infer inside extends, such as in the example below:

  type A<T> = {};
  type B = {} extends infer T extends {} ? A<T> : never;

  TypeScript code that does this should now be parsed correctly.

• Use WebAssembly.instantiateStreaming if available (#1036, #1900)

  Currently the WebAssembly version of esbuild uses fetch to download esbuild.wasm and then WebAssembly.instantiate to compile it. There is a newer API called WebAssembly.instantiateStreaming that both downloads and compiles at the same time, which can be a performance improvement if both downloading and compiling are slow. With this release, esbuild now attempts to use WebAssembly.instantiateStreaming and falls back to the original approach if that fails.

  The implementation for this builds on a PR by @lbwa.

• Preserve Webpack comments inside constructor calls (#2439)

  This improves the use of esbuild as a faster TypeScript-to-JavaScript frontend for Webpack, which has special magic comments inside new Worker() expressions that affect Webpack's behavior.