@biomejs/biome

1.7.0 (2024-04-15)

Analyzer

Bug fixes

• Now Biome can detect the script language in Svelte and Vue script blocks more reliably (#2245). Contributed by @Sec-ant

• useExhaustiveDependencies no longer reports recursive calls as missing dependencies (#2361). Contributed by @arendjr

• useExhaustiveDependencies correctly reports missing dependencies declared using function declarations (#2362). Contributed by @arendjr

• Biome now can handle .svelte and .vue files with CRLF as the end-of-line sequence. Contributed by @Sec-ant

• noMisplacedAssertion no longer reports method calls by describe, test, it objects (e.g. test.each([])()) (#2443). Contributed by @unvalley.

• Biome now can handle .vue files with generic components (#2456).

  <script generic="T extends Record<string, any>" lang="ts" setup>
  //...
  </script>
  

  Contributed by @Sec-ant

Enhancements

• Complete the well-known file lists for JSON-like files. Trailing commas are allowed in .jsonc files by default. Some well-known files like tsconfig.json and .babelrc don't use the .jsonc extension but still allow comments and trailing commas. While others, such as .eslintrc.json, only allow comments. Biome is able to identify these files and adjusts the json.parser.allowTrailingCommas option accordingly to ensure they are correctly parsed. Contributed by @Sec-ant

• Fix dedent logic inconsistent with prettier where the indent-style is space and the indent-width is not 2. Contributed by @mdm317

CLI

New features

• Add a command to migrate from ESLint

  biome migrate eslint allows you to migrate an ESLint configuration to Biome. The command supports legacy ESLint configurations and new flat ESLint configurations. Legacy ESLint configurations using the YAML format are not supported.

  When loading a legacy ESLint configuration, Biome resolves the extends field. It resolves both shared configurations and plugin presets! To do this, it invokes Node.js.

  Biome relies on the metadata of its rules to determine the equivalent rule of an ESLint rule. A Biome rule is either inspired or roughly identical to an ESLint rules. By default, inspired and nursery rules are excluded from the migration. You can use the CLI flags --include-inspired and --include-nursery to migrate them as well.

  Note that this is a best-effort approach. You are not guaranteed to get the same behavior as ESLint.

  Given the following ESLint configuration:

  {
        "ignore_patterns": ["**/*.test.js"],
        "globals": { "var2": "readonly" },
        "rules": {
            "eqeqeq": "error"
        },
        "overrides": [{
            "files": ["lib/*.js"],
            "rules": {
              "default-param-last": "off"
            }
        }]
  }
  

  biome migrate eslint --write changes the Biome configuration as follows:

  {
    "linter": {
      "rules": {
        "recommended": false,
        "suspicious": {
          "noDoubleEquals": "error"
        }
      }
    },
    "javascript": { "globals": ["var2"] },
    "overrides": [{
      "include": ["lib/*.js"],
      "linter": {
        "rules": {
          "style": {
            "useDefaultParameterLast": "off"
          }
        }
      }
    }]
  }
  

  Also, if the working directory contains .eslintignore, then Biome migrates the glob patterns. Nested .eslintignore in subdirectories and negated glob patterns are not supported.

  If you find any issue, please don't hesitate to report them.

  Contributed by @Conaclos

• Added two new options to customise the emitted output of the CLI: --reporter=json and --reporter=json-pretty. With --reporter=json, the diagnostics and the summary will be printed in the terminal in JSON format. With --reporter=json-pretty, you can print the same information, but formatted using the same options of your configuration.

  NOTE: the shape of the JSON is considered experimental, and the shape of the JSON might change in the future.

  <details> <summary>Example of output when running `biome format` command</summary> ```json { "summary": { "changed": 0, "unchanged": 1, "errors": 1, "warnings": 0, "skipped": 0, "suggestedFixesSkipped": 0, "diagnosticsNotPrinted": 0 }, "diagnostics": [ { "category": "format", "severity": "error", "description": "Formatter would have printed the following content:", "message": [ { "elements": [], "content": "Formatter would have printed the following content:" } ], "advices": { "advices": [ { "diff": { "dictionary": " statement();\n", "ops": [ { "diffOp": { "delete": { "range": [0, 2] } } }, { "diffOp": { "equal": { "range": [2, 12] } } }, { "diffOp": { "delete": { "range": [0, 2] } } }, { "diffOp": { "equal": { "range": [12, 13] } } }, { "diffOp": { "delete": { "range": [0, 2] } } }, { "diffOp": { "insert": { "range": [13, 15] } } } ] } } ] }, "verboseAdvices": { "advices": [] }, "location": { "path": { "file": "format.js" }, "span": null, "sourceCode": null }, "tags": [], "source": null } ], "command": "format" } ``` </details>

• Added new --staged flag to the check, format and lint subcommands.

  This new option allows users to apply the command only to the files that are staged (the ones that will be committed), which can be very useful to simplify writing git hook scripts such as pre-commit. Contributed by @castarco

Enhancements

• Improve support of .prettierignore when migrating from Prettier

  Now, Biome translates most of the glob patterns in .prettierignore to the equivalent Biome ignore pattern. Only negated glob patterns are not supported.

  Contributed by @Conaclos

• Support JavaScript configuration files when migrating from Prettier

  biome migrate prettier is now able to migrate Prettier configuration files ending with js, mjs, or cjs extensions. To do this, Biome invokes Node.js.

  Also, embedded Prettier configurations in package.json are now supported.

  Contributed by @Conaclos

• Support overrides field in Prettier configuration files when migrating from Prettier. Contributed by @Conaclos

• Support passing a file path to the --config-path flag or the BIOME_CONFIG_PATH environment variable.

  Now you can pass a .json/.jsonc file path with any filename to the --config-path flag or the BIOME_CONFIG_PATH environment variable. This will disable the configuration auto-resolution and Biome will try to read the configuration from the said file path (#2265).

  biome format --config-path=../biome.json ./src
  

  Contributed by @Sec-ant

Bug fixes

• Biome now tags the diagnostics emitted by organizeImports and formatter with correct severity levels, so they will be properly filtered by the flag --diagnostic-level (#2288). Contributed by @Sec-ant

• Biome now correctly filters out files that are not present in the current directory when using the --changed flag #1996. Contributed by @castarco

• Biome now skips traversing fifo or socket files (#2311). Contributed by @Sec-ant

• Biome now resolves configuration files exported from external libraries in extends from the working directory (CLI) or project root (LSP). This is the documented behavior and previous resolution behavior is considered as a bug (#2231). Contributed by @Sec-ant

Configuration

Bug fixes

• Now setting group level all to false can disable recommended rules from that group when top level recommended is true or unset. Contributed by @Sec-ant

• Biome configuration files can correctly extends .jsonc configuration files now (#2279). Contributed by @Sec-ant

• Fixed the JSON schema for React hooks configuration (#2396). Contributed by @arendjr

Enhancements

• Biome now displays the location of a parsing error for its configuration file (#1627).

  Previously, when Biome encountered a parsing error in its configuration file, it didn't indicate the location of the error. It now displays the name of the configuration file and the range where the error occurred.

  Contributed by @Conaclos

• options is no longer required for rules without any options (#2313).

  Previously, the JSON schema required to set options to null when an object is used to set the diagnostic level of a rule without any option. However, if options is set to null, Biome emits an error.

  The schema is now fixed and it no longer requires specifying options. This makes the following configuration valid:

  {
    "linter": {
      "rules": {
        "style": {
          "noDefaultExport": {
            "level": "off"
          }
        }
      }
    }
  }
  

  Contributed by @Conaclos

Editors

Bug fixes

• Biome extension is now able to parse the JSX syntax in files that associated with the javascript language identifier. This is an ad hoc fix, because in the React world, .js files are allowed to include JSX syntax, and these files are often associated with the javascript language identifier in most of the editors. Plus, some editor extensions will also associate .jsx files with the javascript language identifier. Relative links: discussion, #2085. Contributed by @Sec-ant

Formatter

Bug fixes

• Fix #2291 by correctly handle comment placement for JSX spread attributes and JSX spread children. Contributed by @ah-yu

JavaScript APIs

Linter

Promoted rules

New rules are incubated in the nursery group. Once stable, we promote them to a stable group. The following rules are promoted:

• complecity/noExcessiveNestedTestSuites
• complexity/noUselessTernary
• correctness/useJsxKeyInIterable
• performance/noBarrelFile
• performance/noReExportAll
• style/noNamespaceImport
• style/useNodeAssertStrict
• suspicious/noDuplicateTestHooks
• suspicious/noExportsInTest
• suspicious/noFocusedTests
• suspicious/noSkippedTests
• suspicious/noSuspiciousSemicolonInJsx

New features

• Add a new option jsxRuntime to the javascript configuration. When set to reactClassic, the noUnusedImports and useImportType rules use this information to make exceptions for the React global that is required by the React Classic JSX transform.

  This is only necessary for React users who haven't upgraded to the new JSX transform.

  Contributed by @Conaclos and @arendjr

• Implement #2043: The React rule useExhaustiveDependencies is now also compatible with Preact hooks imported from preact/hooks or preact/compat. Contributed by @arendjr

• Add rule noFlatMapIdentity to disallow unnecessary callback use on flatMap. Contributed by @isnakode

• Add rule noConstantMathMinMaxClamp, which disallows using Math.min and Math.max to clamp a value where the result itself is constant. Contributed by @mgomulak

Enhancements

• style/useFilenamingConvention now allows prefixing a filename with + (#2341).

  This is a convention used by Sveltekit and Vike.

  Contributed by @Conaclos

• style/useNamingConvention now accepts PascalCase for local and top-level variables.

  This allows supporting local variables that hold a component or a regular class. The following code is now accepted:

  function loadComponent() {
    const Component = getComponent();
    return <Component />;
  }
  

  Contributed by @Conaclos

• complexity/useLiteralKeys no longer report computed properties named __proto__ (#2430).

  In JavaScript, {["__proto__"]: null} and {__proto__: null} have not the same semantic. The first code set a regular property to null. The second one set the prototype of the object to null. See the MDN Docs for more details.

  The rule now ignores computed properties named __proto__.

  Contributed by @Conaclos

Bug fixes

• Lint rules useNodejsImportProtocol, useNodeAssertStrict, noRestrictedImports, noNodejsModules will no longer check declare module statements anymore. Contributed by @Sec-ant

• style/useNamingConvention now accepts any case for variables from object destructuring (#2332).

  The following name is now ignored:

  const { Strange_Style } = obj;
  

  Previously, the rule renamed this variable. This led to a runtime error.

  Contributed by @Conaclos

Parser

Bug fixes

• Fixed an issue when Unicode surrogate pairs were encoded in JavaScript strings using an escape sequence (#2384). Contributed by @arendjr