fix(deps): update dependency esbuild to v0.14.28

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
esbuild	0.14.11 -> 0.14.28

---

Release Notes

evanw/esbuild

v0.14.28

Compare Source

• Add support for some new CSS rules (#​2115, #​2116, #​2117)

  This release adds support for @font-palette-values, @counter-style, and @font-feature-values. This means esbuild will now pretty-print and minify these rules better since it now better understands the internal structure of these rules:

  /* Original code */
  @​font-palette-values Foo { base-palette: 1; }
  @​counter-style bar { symbols: b a r; }
  @​font-feature-values Bop { @​styleset { test: 1; } }
  
  /* Old output (with --minify) */
  @​font-palette-values Foo{base-palette: 1;}@​counter-style bar{symbols: b a r;}@​font-feature-values Bop{@​styleset {test: 1;}}
  
  /* New output (with --minify) */
  @​font-palette-values Foo{base-palette:1}@​counter-style bar{symbols:b a r}@​font-feature-values Bop{@​styleset{test:1}}

• Upgrade to Go 1.18.0 (#​2105)

  Binary executables for this version are now published with Go version 1.18.0. The Go release notes say that the linker generates smaller binaries and that on 64-bit ARM chips, compiled binaries run around 10% faster. On an M1 MacBook Pro, esbuild's benchmark runs approximately 8% faster than before and the binary executable is approximately 4% smaller than before.

  This also fixes a regression from version 0.14.26 of esbuild where the browser builds of the esbuild-wasm package could fail to be bundled due to the use of built-in node libraries. The primary WebAssembly shim for Go 1.18.0 no longer uses built-in node libraries.

v0.14.27

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• Avoid generating an enumerable default import for CommonJS files in Babel mode (#​2097)

  Importing a CommonJS module into an ES module can be done in two different ways. In node mode the default import is always set to module.exports, while in Babel mode the default import passes through to module.exports.default instead. Node mode is triggered when the importing file ends in .mjs, has type: "module" in its package.json file, or the imported module does not have a __esModule marker.

  Previously esbuild always created the forwarding default import in Babel mode, even if module.exports had no property called default. This was problematic because the getter named default still showed up as a property on the imported namespace object, and could potentially interfere with code that iterated over the properties of the imported namespace object. With this release the getter named default will now only be added in Babel mode if the default property exists at the time of the import.

• Fix a circular import edge case regarding ESM-to-CommonJS conversion (#​1894, #​2059)

  This fixes a regression that was introduced in version 0.14.5 of esbuild. Ever since that version, esbuild now creates two separate export objects when you convert an ES module file into a CommonJS module: one for ES modules and one for CommonJS modules. The one for CommonJS modules is written to module.exports and exported from the file, and the one for ES modules is internal and can be accessed by bundling code that imports the entry point (for example, the entry point might import itself to be able to inspect its own exports).

  The reason for these two separate export objects is that CommonJS modules are supposed to see a special export called __esModule which indicates that the module used to be an ES module, while ES modules are not supposed to see any automatically-added export named __esModule. This matters for real-world code both because people sometimes iterate over the properties of ES module export namespace objects and because some people write ES module code containing their own exports named __esModule that they expect other ES module code to be able to read.

  However, this change to split exports into two separate objects broke ES module re-exports in the edge case where the imported module is involved in an import cycle. This happened because the CommonJS module.exports object was no longer mutated as exports were added. Instead it was being initialized at the end of the generated file after the import statements to other modules (which are converted into require() calls). This release changes module.exports initialization to happen earlier in the file and then double-writes further exports to both the ES module and CommonJS module export objects.

  This fix was contributed by @​indutny.

v0.14.26

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• Fix a tree shaking regression regarding var declarations (#​2080, #​2085, #​2098, #​2099)

  Version 0.14.8 of esbuild enabled removal of duplicate function declarations when minification is enabled (see #​610):

  // Original code
  function x() { return 1 }
  console.log(x())
  function x() { return 2 }
  
  // Output (with --minify-syntax)
  console.log(x());
  function x() {
    return 2;
  }

  This transformation is safe because function declarations are "hoisted" in JavaScript, which means they are all done first before any other code is evaluted. This means the last function declaration will overwrite all previous function declarations with the same name.

  However, this introduced an unintentional regression for var declarations in which all but the last declaration was dropped if tree-shaking was enabled. This only happens for top-level var declarations that re-declare the same variable multiple times. This regression has now been fixed:

  // Original code
  var x = 1
  console.log(x)
  var x = 2
  
  // Old output (with --tree-shaking=true)
  console.log(x);
  var x = 2;
  
  // New output (with --tree-shaking=true)
  var x = 1;
  console.log(x);
  var x = 2;

  This case now has test coverage.

• Add support for parsing "instantiation expressions" from TypeScript 4.7 (#​2038)

  The upcoming version of TypeScript now lets you specify <...> type parameters on a JavaScript identifier without using a call expression:

  const ErrorMap = Map<string, Error>;  // new () => Map<string, Error>
  const errorMap = new ErrorMap();  // Map<string, Error>

  With this release, esbuild can now parse these new type annotations. This feature was contributed by @​g-plane.

• Avoid new Function in esbuild's library code (#​2081)

  Some JavaScript environments such as Cloudflare Workers or Deno Deploy don't allow new Function because they disallow dynamic JavaScript evaluation. Previously esbuild's WebAssembly-based library used this to construct the WebAssembly worker function. With this release, the code is now inlined without using new Function so it will be able to run even when this restriction is in place.

• Drop superfluous __name() calls (#​2062)

  When the --keep-names option is specified, esbuild inserts calls to a __name helper function to ensure that the .name property on function and class objects remains consistent even if the function or class name is renamed to avoid a name collision or because name minification is enabled. With this release, esbuild will now try to omit these calls to the __name helper function when the name of the function or class object was not renamed during the linking process after all:

  // Original code
  import { foo as foo1 } from 'data:text/javascript,export function foo() { return "foo1" }'
  import { foo as foo2 } from 'data:text/javascript,export function foo() { return "foo2" }'
  console.log(foo1.name, foo2.name)
  
  // Old output (with --bundle --keep-names)
  (() => {
    var __defProp = Object.defineProperty;
    var __name = (target, value) => __defProp(target, "name", { value, configurable: true });
    function foo() {
      return "foo1";
    }
    __name(foo, "foo");
    function foo2() {
      return "foo2";
    }
    __name(foo2, "foo");
    console.log(foo.name, foo2.name);
  })();
  
  // New output (with --bundle --keep-names)
  (() => {
    var __defProp = Object.defineProperty;
    var __name = (target, value) => __defProp(target, "name", { value, configurable: true });
    function foo() {
      return "foo1";
    }
    function foo2() {
      return "foo2";
    }
    __name(foo2, "foo");
    console.log(foo.name, foo2.name);
  })();

  Notice how one of the calls to __name is now no longer printed. This change was contributed by @​indutny.

v0.14.25

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• Reduce minification of CSS transforms to avoid Safari bugs (#​2057)

  In Safari, applying a 3D CSS transform to an element can cause it to render in a different order than applying a 2D CSS transform even if the transformation matrix is identical. I believe this is a bug in Safari because the CSS transform specification doesn't seem to distinguish between 2D and 3D transforms as far as rendering order:

  For elements whose layout is governed by the CSS box model, any value other than none for the transform property results in the creation of a stacking context.

  This bug means that minifying a 3D transform into a 2D transform must be avoided even though it's a valid transformation because it can cause rendering differences in Safari. Previously esbuild sometimes minified 3D CSS transforms into 2D CSS transforms but with this release, esbuild will no longer do that:

  /* Original code */
  div { transform: matrix3d(2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1) }
  
  /* Old output (with --minify) */
  div{transform:scale(2)}
  
  /* New output (with --minify) */
  div{transform:scale3d(2,2,1)}

• Minification now takes advantage of the ?. operator

  This adds new code minification rules that shorten code with the ?. optional chaining operator when the result is equivalent:

  // Original code
  let foo = (x) => {
    if (x !== null && x !== undefined) x.y()
    return x === null || x === undefined ? undefined : x.z
  }
  
  // Old output (with --minify)
  let foo=n=>(n!=null&&n.y(),n==null?void 0:n.z);
  
  // New output (with --minify)
  let foo=n=>(n?.y(),n?.z);

  This only takes effect when minification is enabled and when the configured target environment is known to support the optional chaining operator. As always, make sure to set --target= to the appropriate language target if you are running the minified code in an environment that doesn't support the latest JavaScript features.

• Add source mapping information for some non-executable tokens (#​1448)

  Code coverage tools can generate reports that tell you if any code exists that has not been run (or "covered") during your tests. You can use this information to add additional tests for code that isn't currently covered.

  Some popular JavaScript code coverage tools have bugs where they incorrectly consider lines without any executable code as uncovered, even though there's no test you could possibly write that would cause those lines to be executed. For example, they apparently complain about the lines that only contain the trailing } token of an object literal.

  With this release, esbuild now generates source mappings for some of these trailing non-executable tokens. This may not successfully work around bugs in code coverage tools because there are many non-executable tokens in JavaScript and esbuild doesn't map them all (the drawback of mapping these extra tokens is that esbuild will use more memory, build more slowly, and output a bigger source map). The true solution is to fix the bugs in the code coverage tools in the first place.

• Fall back to WebAssembly on Android x64 (#​2068)

  Go's compiler supports trivial cross-compiling to almost all platforms without installing any additional software other than the Go compiler itself. This has made it very easy for esbuild to publish native binary executables for many platforms. However, it strangely doesn't support cross-compiling to Android x64 without installing the Android build tools. So instead of publishing a native esbuild binary executable to npm, this release publishes a WebAssembly fallback build. This is essentially the same as the esbuild-wasm package but it's installed automatically when you install the esbuild package on Android x64. So packages that depend on the esbuild package should now work on Android x64. If you want to use a native binary executable of esbuild on Android x64, you may be able to build it yourself from source after installing the Android build tools.

• Update to Go 1.17.8

  The version of the Go compiler used to compile esbuild has been upgraded from Go 1.17.7 to Go 1.17.8, which fixes the RISC-V 64-bit build. Compiler optimizations for the RISC-V 64-bit build have now been re-enabled.

v0.14.24

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• Allow es2022 as a target environment (#​2012)

  TypeScript recently added support for es2022 as a compilation target so esbuild now supports this too. Support for this is preliminary as there is no published ES2022 specification yet (i.e. https://tc39.es/ecma262/2021/ exists but https://tc39.es/ecma262/2022/ is a 404 error). The meaning of esbuild's es2022 target may change in the future when the specification is finalized. Right now I have made the es2022 target enable support for the syntax-related finished proposals that are marked as 2022:

  • Class fields
  • Class private members
  • Class static blocks
  • Ergonomic class private member checks
  • Top-level await

  I have also included the "arbitrary module namespace names" feature since I'm guessing it will end up in the ES2022 specification (this syntax feature was added to the specification without a proposal). TypeScript has not added support for this yet.

• Match define to strings in index expressions (#​2050)

  With this release, configuring --define:foo.bar=baz now matches and replaces both foo.bar and foo['bar'] expressions in the original source code. This is necessary for people who have enabled TypeScript's noPropertyAccessFromIndexSignature feature, which prevents you from using normal property access syntax on a type with an index signature such as in the following code:

  declare let foo: { [key: string]: any }
  foo.bar // This is a type error if noPropertyAccessFromIndexSignature is enabled
  foo['bar']

  Previously esbuild would generate the following output with --define:foo.bar=baz:

  baz;
  foo["bar"];

  Now esbuild will generate the following output instead:

  baz;
  baz;

• Add --mangle-quoted to mangle quoted properties (#​218)

  The --mangle-props= flag tells esbuild to automatically rename all properties matching the provided regular expression to shorter names to save space. Previously esbuild never modified the contents of string literals. In particular, --mangle-props=_ would mangle foo._bar but not foo['_bar']. There are some coding patterns where renaming quoted property names is desirable, such as when using TypeScript's noPropertyAccessFromIndexSignature feature or when using TypeScript's discriminated union narrowing behavior:

  interface Foo { _foo: string }
  interface Bar { _bar: number }
  declare const value: Foo | Bar
  console.log('_foo' in value ? value._foo : value._bar)

  The '_foo' in value check tells TypeScript to narrow the type of value to Foo in the true branch and to Bar in the false branch. Previously esbuild didn't mangle the property name '_foo' because it was inside a string literal. With this release, you can now use --mangle-quoted to also rename property names inside string literals:

  // Old output (with --mangle-props=_)
  console.log("_foo" in value ? value.a : value.b);
  
  // New output (with --mangle-props=_ --mangle-quoted)
  console.log("a" in value ? value.a : value.b);

• Parse and discard TypeScript export as namespace statements (#​2070)

  TypeScript .d.ts type declaration files can sometimes contain statements of the form export as namespace foo;. I believe these serve to declare that the module adds a property of that name to the global object. You aren't supposed to feed .d.ts files to esbuild so this normally doesn't matter, but sometimes esbuild can end up having to parse them. One such case is if you import a type-only package who's main field in package.json is a .d.ts file.

  Previously esbuild only allowed export as namespace statements inside a declare context:

  declare module Foo {
    export as namespace foo;
  }

  Now esbuild will also allow these statements outside of a declare context:

  export as namespace foo;

  These statements are still just ignored and discarded.

• Strip import assertions from unrecognized import() expressions (#​2036)

  The new "import assertions" JavaScript language feature adds an optional second argument to dynamic import() expressions, which esbuild does support. However, this optional argument must be stripped when targeting older JavaScript environments for which this second argument would be a syntax error. Previously esbuild failed to strip this second argument in cases when the first argument to import() wasn't a string literal. This problem is now fixed:

  // Original code
  console.log(import(foo, { assert: { type: 'json' } }))
  
  // Old output (with --target=es6)
  console.log(import(foo, { assert: { type: "json" } }));
  
  // New output (with --target=es6)
  console.log(import(foo));

• Remove simplified statement-level literal expressions (#​2063)

  With this release, esbuild now removes simplified statement-level expressions if the simplified result is a literal expression even when minification is disabled. Previously this was only done when minification is enabled. This change was only made because some people are bothered by seeing top-level literal expressions. This change has no effect on code behavior.

• Ignore .d.ts rules in paths in tsconfig.json files (#​2074, #​2075)

  TypeScript's tsconfig.json configuration file has a paths field that lets you remap import paths to alternative files on the file system. This field is interpreted by esbuild during bundling so that esbuild's behavior matches that of the TypeScript type checker. However, people sometimes override import paths to JavaScript files to instead point to a .d.ts TypeScript type declaration file for that JavaScript file. The intent of this is to just use the remapping for type information and not to actually import the .d.ts file during the build.

  With this release, esbuild will now ignore rules in paths that result in a .d.ts file during path resolution. This means code that does this should now be able to be bundled without modifying its tsconfig.json file to remove the .d.ts rule. This change was contributed by @​magic-akari.

• Disable Go compiler optimizations for the Linux RISC-V 64bit build (#​2035)

  Go's RISC-V 64bit compiler target has a fatal compiler optimization bug that causes esbuild to crash when it's run: https://github.com/golang/go/issues/51101. As a temporary workaround until a version of the Go compiler with the fix is published, Go compiler optimizations have been disabled for RISC-V. The 7.7mb esbuild binary executable for RISC-V is now 8.7mb instead. This workaround was contributed by @​piggynl.

v0.14.23

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• Update feature database to indicate that node 16.14+ supports import assertions (#​2030)

  Node versions 16.14 and above now support import assertions according to these release notes. This release updates esbuild's internal feature compatibility database with this information, so esbuild no longer strips import assertions with --target=node16.14:

  // Original code
  import data from './package.json' assert { type: 'json' }
  console.log(data)
  
  // Old output (with --target=node16.14)
  import data from "./package.json";
  console.log(data);
  
  // New output (with --target=node16.14)
  import data from "./package.json" assert { type: "json" };
  console.log(data);

• Basic support for CSS @layer rules (#​2027)

  This adds basic parsing support for a new CSS feature called @layer that changes how the CSS cascade works. Adding parsing support for this rule to esbuild means esbuild can now minify the contents of @layer rules:

  /* Original code */
  @​layer a {
    @​layer b {
      div {
        color: yellow;
        margin: 0.0px;
      }
    }
  }
  
  /* Old output (with --minify) */
  @​layer a{@​layer b {div {color: yellow; margin: 0px;}}}
  
  /* New output (with --minify) */
  @​layer a.b{div{color:#ff0;margin:0}}

  You can read more about @layer here:

  • Documentation: https://developer.mozilla.org/en-US/docs/Web/CSS/[@​layer](https://togithub.com/layer)
  • Motivation: https://developer.chrome.com/blog/cascade-layers/

  Note that the support added in this release is only for parsing and printing @layer rules. The bundler does not yet know about these rules and bundling with @layer may result in behavior changes since these new rules have unusual ordering constraints that behave differently than all other CSS rules. Specifically the order is derived from the first instance while with every other CSS rule, the order is derived from the last instance.

v0.14.22

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• Preserve whitespace for token lists that look like CSS variable declarations (#​2020)

  Previously esbuild removed the whitespace after the CSS variable declaration in the following CSS:

  /* Original input */
  @​supports (--foo: ){html{background:green}}
  
  /* Previous output */
  @​supports (--foo:){html{background:green}}

  However, that broke rendering in Chrome as it caused Chrome to ignore the entire rule. This did not break rendering in Firefox and Safari, so there's a browser bug either with Chrome or with both Firefox and Safari. In any case, esbuild now preserves whitespace after the CSS variable declaration in this case.

• Ignore legal comments when merging adjacent duplicate CSS rules (#​2016)

  This release now generates more compact minified CSS when there are legal comments in between two adjacent rules with identical content:

  /* Original code */
  a { color: red }
  /* @​preserve */
  b { color: red }
  
  /* Old output (with --minify) */
  a{color:red}/* @​preserve */b{color:red}
  
  /* New output (with --minify) */
  a,b{color:red}/* @​preserve */

• Block onResolve and onLoad until onStart ends (#​1967)

  This release changes the semantics of the onStart callback. All onStart callbacks from all plugins are run concurrently so that a slow plugin doesn't hold up the entire build. That's still the case. However, previously the only thing waiting for the onStart callbacks to finish was the end of the build. This meant that onResolve and/or onLoad callbacks could sometimes run before onStart had finished. This was by design but violated user expectations. With this release, all onStart callbacks must finish before any onResolve and/or onLoad callbacks are run.

• Add a self-referential default export to the JS API (#​1897)

  Some people try to use esbuild's API using import esbuild from 'esbuild' instead of import * as esbuild from 'esbuild' (i.e. using a default import instead of a namespace import). There is no default export so that wasn't ever intended to work. But it would work sometimes depending on which tools you used and how they were configured so some people still wrote code this way. This release tries to make that work by adding a self-referential default export that is equal to esbuild's module namespace object.

  More detail: The published package for esbuild's JS API is in CommonJS format, although the source code for esbuild's JS API is in ESM format. The original ESM code for esbuild's JS API has no export named default so using a default import like this doesn't work with Babel-compatible toolchains (since they respect the semantics of the original ESM code). However, it happens to work with node-compatible toolchains because node's implementation of importing CommonJS from ESM broke compatibility with existing conventions and automatically creates a default export which is set to module.exports. This is an unfortunate compatibility headache because it means the default import only works sometimes. This release tries to fix this by explicitly creating a self-referential default export. It now doesn't matter if you do esbuild.build(), esbuild.default.build(), or esbuild.default.default.build() because they should all do the same thing. Hopefully this means people don't have to deal with this problem anymore.

• Handle write errors when esbuild's child process is killed (#​2007)

  If you type Ctrl+C in a terminal when a script that uses esbuild's JS library is running, esbuild's child process may be killed before the parent process. In that case calls to the write() syscall may fail with an EPIPE error. Previously this resulted in an uncaught exception because esbuild didn't handle this case. Starting with this release, esbuild should now catch these errors and redirect them into a general The service was stopped error which should be returned from whatever top-level API calls were in progress.

• Better error message when browser WASM bugs are present (#​1863)

  Safari's WebAssembly implementation appears to be broken somehow, at least when running esbuild. Sometimes this manifests as a stack overflow and sometimes as a Go panic. Previously a Go panic resulted in the error message Can't find variable: fs but this should now result in the Go panic being printed to the console. Using esbuild's WebAssembly library in Safari is still broken but now there's a more helpful error message.

  More detail: When Go panics, it prints a stack trace to stderr (i.e. file descriptor 2). Go's WebAssembly shim calls out to node's fs.writeSync() function to do this, and it converts calls to fs.writeSync() into calls to console.log() in the browser by providing a shim for fs. However, Go's shim code stores the shim on window.fs in the browser. This is undesirable because it pollutes the global scope and leads to brittle code that can break if other code also uses window.fs. To avoid this, esbuild shadows the global object by wrapping Go's shim. But that broke bare references to fs since the shim is no longer stored on window.fs. This release now stores the shim in a local variable named fs so that bare references to fs work correctly.

• Undo incorrect dead-code elimination with destructuring (#​1183)

  Previously esbuild eliminated these statements as dead code if tree-shaking was enabled:

  let [a] = {}
  let { b } = null

  This is incorrect because both of these lines will throw an error when evaluated. With this release, esbuild now preserves these statements even when tree shaking is enabled.

• Update to Go 1.17.7

  The version of the Go compiler used to compile esbuild has been upgraded from Go 1.17.6 to Go 1.17.7, which contains a few compiler and security bug fixes.

v0.14.21

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• Handle an additional browser map edge case (#​2001, #​2002)

  There is a community convention around the browser field in package.json that allows remapping import paths within a package when the package is bundled for use within a browser. There isn't a rigorous definition of how it's supposed to work and every bundler implements it differently. The approach esbuild uses is to try to be "maximally compatible" in that if at least one bundler exhibits a particular behavior regarding the browser map that allows a mapping to work, then esbuild also attempts to make that work.

  I have a collection of test cases for this going here: https://github.com/evanw/package-json-browser-tests. However, I was missing test coverage for the edge case where a package path import in a subdirectory of the package could potentially match a remapping. The "maximally compatible" approach means replicating bugs in Browserify's implementation of the feature where package paths are mistaken for relative paths and are still remapped. Here's a specific example of an edge case that's now handled:

  • entry.js:

    require('pkg/sub')

  • node_modules/pkg/package.json:

    {
      "browser": {
        "./sub": "./sub/foo.js",
        "./sub/sub": "./sub/bar.js"
      }
    }

  • node_modules/pkg/sub/foo.js:

    require('sub')

  • node_modules/pkg/sub/bar.js:

    console.log('works')

  The import path sub in require('sub') is mistaken for a relative path by Browserify due to a bug in Browserify, so Browserify treats it as if it were ./sub instead. This is a Browserify-specific behavior and currently doesn't happen in any other bundler (except for esbuild, which attempts to replicate Browserify's bug).

  Previously esbuild was incorrectly resolving ./sub relative to the top-level package directory instead of to the subdirectory in this case, which meant ./sub was incorrectly matching "./sub": "./sub/foo.js" instead of "./sub/sub": "./sub/bar.js". This has been fixed so esbuild can now emulate Browserify's bug correctly in this edge case.

• Support for esbuild with Linux on RISC-V 64bit (#​2000)

  With this release, esbuild now has a published binary executable for the RISC-V 64bit architecture in the esbuild-linux-riscv64 npm package. This change was contributed by @​piggynl.

v0.14.20

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• Fix property mangling and keyword properties (#​1998)

  Previously enabling property mangling with --mangle-props= failed to add a space before property names after a keyword. This bug has been fixed:

  // Original code
  class Foo {
    static foo = {
      get bar() {}
    }
  }
  
  // Old output (with --minify --mangle-props=.)
  class Foo{statics={gett(){}}}
  
  // New output (with --minify --mangle-props=.)
  class Foo{static s={get t(){}}}

v0.14.19

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• Special-case const inlining at the top of a scope (#​1317, #​1981)

  The minifier now inlines const variables (even across modules during bundling) if a certain set of specific requirements are met:

  • All const variables to be inlined are at the top of their scope
  • That scope doesn't contain any import or export statements with paths
  • All constants to be inlined are null, undefined, true, false, an integer, or a short real number
  • Any expression outside of a small list of allowed ones stops constant identification

  Practically speaking this basically means that you can trigger this optimization by just putting the constants you want inlined into a separate file (e.g. constants.js) and bundling everything together.

  These specific conditions are present to avoid esbuild unintentionally causing any behavior changes by inlining constants when the variable reference could potentially be evaluated before being declared. It's possible to identify more cases where constants can be inlined but doing so may require complex call graph analysis so it has not been implemented. Although these specific heuristics may change over time, this general approach to constant inlining should continue to work going forward.

  Here's an example:

  // Original code
  const bold = 1 << 0;
  const italic = 1 << 1;
  const underline = 1 << 2;
  const font = bold | italic | underline;
  console.log(font);
  
  // Old output (with --minify --bundle)
  (()=>{var o=1<<0,n=1<<1,c=1<<2,t=o|n|c;console.log(t);})();
  
  // New output (with --minify --bundle)
  (()=>{console.log(7);})();

v0.14.18

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• Add the --mangle-cache= feature (#​1977)

  This release adds a cache API for the newly-released --mangle-props= feature. When enabled, all mangled property renamings are recorded in the cache during the initial build. Subsequent builds reuse the renamings stored in the cache and add additional renamings for any newly-added properties. This has a few consequences:

  • You can customize what mangled properties are renamed to by editing the cache before passing it to esbuild (the cache is a map of the original name to the mangled name).

  • The cache serves as a list of all properties that were mangled. You can easily scan it to see if there are any unexpected property renamings.

  • You can disable mangling for individual properties by setting the renamed value to false instead of to a string. This is similar to the --reserve-props= setting but on a per-property basis.

  • You can ensure consistent renaming between builds (e.g. a main-thread file and a web worker, or a library and a plugin). Without this feature, each build would do an independent renaming operation and the mangled property names likely wouldn't be consistent.

  Here's how to use it:

  • CLI

    $ esbuild example.ts --mangle-props=_$ --mangle-cache=cache.json

  • JS API

    let result = await esbuild.build({
      entryPoints: ['example.ts'],
      mangleProps: /_$/,
      mangleCache: {
        customRenaming_: '__c',
        disabledRenaming_: false,
      },
    })
    let updatedMangleCache = result.mangleCache

  • Go API

    result := api.Build(api.BuildOptions{
      EntryPoints: []string{"example.ts"},
      MangleProps: "_$",
      MangleCache: map[string]interface{}{
        "customRenaming_":   "__c",
        "disabledRenaming_": false,
      },
    })
    updatedMangleCache := result.MangleCache

  The above code would do something like the following:

  // Original code
  x = {
    customRenaming_: 1,
    disabledRenaming_: 2,
    otherProp_: 3,
  }
  
  // Generated code
  x = {
    __c: 1,
    disabledRenaming_: 2,
    a: 3
  };
  
  // Updated mangle cache
  {
    "customRenaming_": "__c",
    "disabledRenaming_": false,
    "otherProp_": "a"
  }

• Add opera and ie as possible target environments

  You can now target Opera and/or Internet Explorer using the --target= setting. For example, --target=opera45,ie9 targets Opera 45 and Internet Explorer 9. This change does not add any additional features to esbuild's code transformation pipeline to transform newer syntax so that it works in Internet Explorer. It just adds information about what features are supported in these browsers to esbuild's internal feature compatibility table.

• Minify typeof x !== 'undefined' to typeof x < 'u'

  This release introduces a small improvement for code that does a lot of typeof checks against undefined:

  // Original code
  y = typeof x !== 'undefined';
  
  // Old output (with --minify)
  y=typeof x!="undefined";
  
  // New output (with --minify)
  y=typeof x<"u";

  This transformation is only active when minification is enabled, and is disabled if the language target is set lower than ES2020 or if Internet Explorer is set as a target environment. Before ES2020, implementations were allowed to return non-standard values from the typeof operator for a few objects. Internet Explorer took advantage of this to sometimes return the string 'unknown' instead of 'undefined'. But this has been removed from the specification and Internet Explorer was the only engine to do this, so this minification is valid for code that does not need to target Internet Explorer.

v0.14.17

Compare Source

• Attempt to fix an install script issue on Ubuntu Linux (#​1711)

  There have been some reports of esbuild failing to install on Ubuntu Linux for a while now. I haven't been able to reproduce this myself due to lack of reproduction instructions until today, when I learned that the issue only happens when you install node from the Snap Store instead of downloading the official version of node.

  The problem appears to be that when node is installed from the Snap Store, install scripts are run with stderr not being writable? This then appears to cause a problem for esbuild's install script when it uses execFileSync to validate that the esbuild binary is working correctly. This throws the error EACCES: permission denied, write even though this particular command never writes to stderr.

  Node's documentation says that stderr for execFileSync defaults to that of the parent process. Forcing it to 'pipe' instead appears to fix the issue, although I still don't fully understand what's happening or why. I'm publishing this small change regardless to see if it fixes this install script edge case.

• Avoid a syntax error due to --mangle-props=. and super() (#​1976)

  This release fixes an issue where passing --mangle-props=. (i.e. telling esbuild to mangle every single property) caused a syntax error with code like this:

  class Foo {}
  class Bar extends Foo {
    constructor() {
      super();
    }
  }

  The problem was that constructor was being renamed to another method, which then made it no longer a constructor, which meant that super() was now a syntax error. I have added a workaround that avoids renaming any property named constructor so that esbuild doesn't generate a syntax error here.

  Despite this fix, I highly recommend not using --mangle-props=. because your code will almost certainly be broken. You will have to manually add every single property that you don't want mangled to --reserve-props= which is an excessive maintenance burden (e.g. reserve parse to use JSON.parse). Instead I recommend using a common pattern for all properties you intend to be mangled that is unlikely to appear in the APIs you use such as "ends in an underscore." This is an opt-in approach instead of an opt-out approach. It also makes it obvious when reading the code which properties will be mangled and which ones won't be.

v0.14.16

Compare Source

• Support property name mangling with some TypeScript syntax features

  The newly-released --mangle-props= feature previously only affected JavaScript syntax features. This release adds support for using mangle props with certain TypeScript syntax features:

  • TypeScript parameter properties

    Parameter properties are a TypeScript-only shorthand way of initializing a class field directly from the constructor argument list. Previously parameter properties were not treated as properties to be mangled. They should now be handled correctly:

    // Original code
    class Foo {
      constructor(public foo_) {}
    }
    new Foo().foo_;
    
    // Old output (with --minify --mangle-props=_)
    class Foo{constructor(c){this.foo_=c}}new Foo().o;
    
    // New output (with --minify --mangle-props=_)
    class Foo{constructor(o){this.c=o}}new Foo().c;

  • TypeScript namespaces

    Namespaces are a TypeScript-only way to add properties to an object. Previously exported namespace members were not treated as properties to be mangled. They should now be handled correctly:

    // Original code
    namespace ns {
      export let foo_ = 1;
      export function bar_(x) {}
    }
    ns.bar_(ns.foo_);
    
    // Old output (with --minify --mangle-props=_)
    var ns;(e=>{e.foo_=1;function t(a){}e.bar_=t})(ns||={}),ns.e(ns.o);
    
    // New output (with --minify --mangle-props=_)
    var ns;(e=>{e.e=1;function o(p){}e.t=o})(ns||={}),ns.t(ns.e);

• Fix property name mangling for lowered class fields

  This release fixes a compiler crash with --mangle-props= and class fields that need to be transformed to older versions of JavaScript. The problem was that doing this is an unusual case where the mangled property name must be represented as a string instead of as a property name, which previously wasn't implemented. This case should now work correctly:

  // Original code
  class Foo {
    static foo_;
  }
  Foo.foo_ = 0;
  
  // New output (with --mangle-props=_ --target=es6)
  class Foo {
  }
  __publicField(Foo, "a");
  Foo.a = 0;

v0.14.15

Compare Source

• Add property name mangling with --mangle-props= (#​218)

  ⚠️ Using this feature can break your code in subtle ways. Do not use this feature unless you know what you are doing, and you know exactly how it will affect both your code and all of your dependencies. ⚠️

  This release introduces property name mangling, which is similar to an existing feature from the popular UglifyJS and Terser JavaScript minifiers. This setting lets you pass a regular expression to esbuild to tell esbuild to automatically rename all properties that match this regular expression. It's useful when you want to minify certain property names in your code either to make the generated code smaller or to somewhat obfuscate your code's intent.

  Here's an example that uses the regular expression `_

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
esbuild	0.14.11 -> 0.14.28

---

to mangle all properties ending in an underscore, such as foo_:

    $ echo 'console.log({ foo_: 0 }.foo_)' | esbuild --mangle-props=_$
    console.log({ a: 0 }.a);

Only mangling properties that end in an underscore is a reasonable heuristic because normal JS code doesn't typically contain identifiers like that. Browser APIs also don't use this naming convention so this also avoids conflicts with browser APIs. If you want to avoid mangling names such as [`__defineGetter__`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/\__defineGetter\_\_) you could consider using a more complex regular expression such as `[^_]_[![WhiteSource Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
esbuild	0.14.11 -> 0.14.28

---

(i.e. must end in a non-underscore followed by an underscore).

This is a separate setting instead of being part of the minify setting because it's an unsafe transformation that does not work on arbitrary JavaScript code. It only works if the provided regular expression matches all of the properties that you want mangled and does not match any of the properties that you don't want mangled. It also only works if you do not under any circumstances reference a property name to be mangled as a string. For example, it means you can't use `Object.defineProperty(obj, 'prop', ...)` or `obj['prop']` with a mangled property. Specifically the following syntax constructs are the only ones eligible for property mangling:

| Syntax                          | Example                 |
|---------------------------------|-------------------------|
| Dot property access             | `x.foo_`                |
| Dot optional chain              | `x?.foo_`               |
| Object properties               | `x = { foo_: y }`       |
| Object methods                  | `x = { foo_() {} }`     |
| Class fields                    | `class x { foo_ = y }`  |
| Class methods                   | `class x { foo_() {} }` |
| Object destructuring binding    | `let { foo_: x } = y`   |
| Object destructuring assignment | `({ foo_: x } = y)`     |
| JSX element names               | `<X.foo_></X.foo_>`     |
| JSX attribute names             | `<X foo_={y} />`        |

You can avoid property mangling for an individual property by quoting it as a string. However, you must consistently use quotes or no quotes for a given property everywhere for this to work. For example, `print({ foo_: 0 }.foo_)` will be mangled into `print({ a: 0 }.a)` while `print({ 'foo_': 0 }['foo_'])` will not be mangled.

When using this feature, keep in mind that property names are only consistently mangled within a single esbuild API call but not across esbuild API calls. Each esbuild API call does an independent property mangling operation so output files generated by two different API calls may mangle the same property to two different names, which could cause the resulting code to behave incorrectly.

If you would like to exclude certain properties from mangling, you can reserve them with the `--reserve-props=` setting. For example, this uses the regular expression `^__.*__[![WhiteSource Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
esbuild	0.14.11 -> 0.14.28

---

to reserve all properties that start and end with two underscores, such as __foo__:

    $ echo 'console.log({ __foo__: 0 }.__foo__)' | esbuild --mangle-props=_$
    console.log({ a: 0 }.a);

    $ echo 'console.log({ __foo__: 0 }.__foo__)' | esbuild --mangle-props=_$ "--reserve-props=^__.*__$"
    console.log({ __foo__: 0 }.__foo__);

• Mark esbuild as supporting node v12+ (#​1970)

  Someone requested that esbuild populate the engines.node field in package.json. This release adds the following to each package.json file that esbuild publishes:

  "engines": {
    "node": ">=12"
  },

  This was chosen because it's the oldest version of node that's currently still receiving support from the node team, and so is the oldest version of node that esbuild supports: https://nodejs.org/en/about/releases/.

• Remove error recovery for invalid // comments in CSS (#​1965)

  Previously esbuild treated // as a comment in CSS and generated a warning, even though comments in CSS use /* ... */ instead. This allowed you to run esbuild on CSS intended for certain CSS preprocessors that support single-line comments.

  However, some people are changing from another build tool to esbuild and have a code base that relies on // being preserved even though it's nonsense CSS and causes the entire surrounding rule to be discarded by the browser. Presumably this nonsense CSS ended up there at some point due to an incorrectly-configured build pipeline and the site now relies on that entire rule being discarded. If esbuild interprets // as a comment, it could cause the rule to no longer be discarded or even cause something else to happen.

  With this release, esbuild no longer treats // as a comment in CSS. It still warns about it but now passes it through unmodified. This means it's no longer possible to run esbuild on CSS code containing single-line comments but it means that esbuild's behavior regarding these nonsensical CSS rules more accurately represents what happens in a browser.

v0.14.14

Compare Source

• Fix bug with filename hashes and the file loader (#​1957)

  This release fixes a bug where if a file name template has the [hash] placeholder (either --entry-names= or --chunk-names=), the hash that esbuild generates didn't include the content of the string generated by the file loader. Importing a file with the file loader causes the imported file to be copied to the output directory and causes the imported value to be the relative path from the output JS file to that copied file. This bug meant that if the --asset-names= setting also contained [hash] and the file loaded with the file loader was changed, the hash in the copied file name would change but the hash of the JS file would not change, which could potentially result in a stale JS file being loaded. Now the hash of the JS file will be changed too which fixes the reload issue.

• Prefer the import condition for entry points (#​1956)

  The exports field in package.json maps package subpaths to file paths. The mapping can be conditional, which lets it vary in different situations. For example, you can have an import condition that applies when the subpath originated from a JS import statement, and a require condition that applies when the subpath originated from a JS require call. These are supposed to be mutually exclusive according to the specification: https://nodejs.org/api/packages.html#conditional-exports.

  However, there's a situation with esbuild where it's not immediately obvious which one should be applied: when a package name is specified as an entry point. For example, this can happen if you do esbuild --bundle some-pkg on the command line. In this situation some-pkg does not originate from either a JS import statement or a JS require call. Previously esbuild just didn't apply the import or require conditions. But that could result in path resolution failure if the package doesn't provide a back-up default condition, as is the case with the is-plain-object package.

  Starting with this release, esbuild will now use the import condition in this case. This appears to be how Webpack and Rollup handle this situation so this change makes esbuild consistent with other tools in the ecosystem. Parcel (the other major bundler) just doesn't handle this case at all so esbuild's behavior is not at odds with Parcel's behavior here.

• Make parsing of invalid @keyframes rules more robust (#​1959)

  This improves esbuild's parsing of certain malformed @keyframes rules to avoid them affecting the following rule. This fix only affects invalid CSS files, and does not change any behavior for files containing valid CSS. Here's an example of the fix:

  /* Original code */
  @​keyframes x { . }
  @​keyframes y { 1% { a: b; } }
  
  /* Old output (with --minify) */
  @​keyframes x{y{1% {a: b;}}}
  
  /* New output (with --minify) */
  @​keyframes x{.}@​keyframes y{1%{a:b}}

v0.14.13

Compare Source

• Be more consistent about external paths (#​619)

  The rules for marking paths as external using --external: grew over time as more special-cases were added. This release reworks the internal representation to be more straightforward and robust. A side effect is that wildcard patterns can now match post-resolve paths in addition to pre-resolve paths. Specifically you can now do --external:./node_modules/* to mark all files in the ./node_modules/ directory as external.

  This is the updated logic:

  • Before path resolution begins, import paths are checked against everything passed via an --external: flag. In addition, if something looks like a package path (i.e. doesn't start with / or ./ or ../), import paths are checked to see if they have that package path as a path prefix (so --external:@​foo/bar matches the import path @foo/bar/baz).

  • After path resolution ends, the absolute paths are checked against everything passed via --external: that doesn't look like a package path (i.e. that starts with / or ./ or ../). But before checking, the pattern is transformed to be relative to the current working directory.

• Attempt to explain why esbuild can't run (#​1819)

  People sometimes try to install esbuild on one OS and then copy the node_modules directory over to another OS without

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