biome.jsonc

{
  "$schema": "https://biomejs.dev/schemas/2.0.0/schema.json",
  "vcs": {
    "enabled": false,
    "clientKind": "git",
    "useIgnoreFile": true,
    "defaultBranch": "beta"
  },
  "formatter": {
    "enabled": true,
    "useEditorconfig": true,
    "indentStyle": "space",
    "includes": ["**", "!**/src/enums/**/*", "!**/src/data/balance/**/*"],
    "lineWidth": 120
  },
  "files": {
    "ignoreUnknown": true,
    // Adding folders to the ignore list is GREAT for performance because it prevents biome from descending into them
    // and having to verify whether each individual file is ignored
    "includes": [
      "**",
      "!**/dist/**/*",
      "!**/build/**/*",
      "!**/coverage/**/*",
      "!**/public/**/*",
      "!**/.github/**/*",
      "!**/node_modules/**/*",
      "!**/.vscode/**/*",
      "!**/typedoc/**/*",
      // TODO: lint css and html?
      "!**/*.css",
      "!**/*.html",
      // TODO: enable linting this file
      "!**/src/data/moves/move.ts",
      // this file is too big
      "!**/src/data/balance/tms.ts"
    ]
  },

  "assist": {
    "actions": {
      "source": {
        "organizeImports": {
          "level": "on",
          "options": {
            "groups": [":ALIAS:", ":NODE:", ":PACKAGE_WITH_PROTOCOL:", ":PACKAGE:", ":PATH:"]
          }
        }
      }
    }
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true,
      "correctness": {
        "noUndeclaredVariables": "off",
        "noUnusedVariables": "error",
        "noSwitchDeclarations": "error",
        "noVoidTypeReturn": "error",
        "noUnusedImports": {
          "level": "error",
          "fix": "safe"
        },
        "noUnusedFunctionParameters": "error",
        "noUnusedLabels": "error",
        "noPrivateImports": "error"
      },
      "style": {
        "useEnumInitializers": "off", // large enums like Moves/Species would make this cumbersome
        "useBlockStatements": {
          "level": "error",
          "fix": "safe"
        },
        "useConst": "error",
        "useImportType": "error",
        "noNonNullAssertion": "off", // TODO: Turn this on ASAP and fix all non-null assertions in non-test files
        "noParameterAssign": "off",
        "useExponentiationOperator": "off", // Too typo-prone and easy to mixup with standard multiplication (* vs **)
        "useDefaultParameterLast": {
          // TODO: Fix spots in the codebase where this flag would be triggered
          // and then set to "error" and re-enable the fixer
          "level": "warn",
          "fix": "none"
        },
        "useSingleVarDeclarator": "off",
        "useNodejsImportProtocol": "off",
        "useTemplate": "off", // string concatenation is faster: https://stackoverflow.com/questions/29055518/are-es6-template-literals-faster-than-string-concatenation
        "useAsConstAssertion": "error",
        "noUnusedTemplateLiteral": "error",
        "useNumberNamespace": "error",
        "noInferrableTypes": "error",
        "noUselessElse": "error",
        "noRestrictedTypes": {
          "level": "error",
          "options": {
            "types": {
              "integer": {
                "message": "This is an alias for 'number' that can provide false impressions of what values can actually be contained in this variable. Use 'number' instead.",
                "use": "number"
              }
            }
          }
        }
      },
      "suspicious": {
        "noDoubleEquals": "error",
        // While this would be a nice rule to enable, the current structure of the codebase makes this infeasible
        // due to being used for move/ability `args` params and save data-related code.
        // This can likely be enabled for all non-utils files once these are eventually reworked, but until then we leave it off.
        "noExplicitAny": "off",
        "noAssignInExpressions": "off",
        "noPrototypeBuiltins": "off",
        "noFallthroughSwitchClause": "error", // Prevents accidental automatic fallthroughs in switch cases (use disable comment if needed)
        "noImplicitAnyLet": "warn", // TODO: Refactor and make this an error
        "noRedeclare": "info", // TODO: Refactor and make this an error
        "noGlobalIsNan": "off",
        "noAsyncPromiseExecutor": "warn", // TODO: Refactor and make this an error
        "noVar": "error",
        "noDocumentCookie": "off" // Firefox has minimal support for the "Cookie Store API"
      },
      "complexity": {
        "noExcessiveCognitiveComplexity": "info", // TODO: Refactor and make this an error
        "useLiteralKeys": "off",
        "noForEach": "off", // Foreach vs for of is not that simple.
        "noUselessSwitchCase": "off", // Explicit > Implicit
        "noUselessConstructor": "error",
        "noBannedTypes": "warn", // TODO: Refactor and make this an error
        "noThisInStatic": "error",
        "noUselessThisAlias": "error",
        "noUselessTernary": "error"
      },
      "performance": {
        "noNamespaceImport": "error",
        "noDelete": "error"
      },
      "nursery": {
        "useAdjacentGetterSetter": "error",
        "noConstantBinaryExpression": "error",
        "noTsIgnore": "error",
        "noAwaitInLoop": "off",
        "useJsonImportAttribute": "off", // "Import attributes are only supported when the '--module' option is set to 'esnext', 'node18', 'nodenext', or 'preserve'. ts(2823)"
        "useIndexOf": "error",
        "useObjectSpread": "error",
        "useNumericSeparators": "off", // TODO: enable?
        "useIterableCallbackReturn": "warn", // TODO: refactor and make "error"
        "noShadow": "warn" // TODO: refactor and make "error"
      }
    }
  },
  "javascript": {
    "formatter": {
      "quoteStyle": "double",
      "arrowParentheses": "asNeeded"
    },
    "parser": {
      "jsxEverywhere": false
    }
  },
  "overrides": [
    {
      "includes": ["**/test/**/*.test.ts"],
      "linter": {
        "rules": {
          "performance": {
            "noDelete": "off", // TODO: evaluate if this is necessary for the test(s) to function
            "noNamespaceImport": "off" // this is required for `vi.spyOn` to work in some tests
          },
          "style": {
            "noNonNullAssertion": "off"
          },
          "nursery": {
            "noFloatingPromises": "error"
          }
        }
      }
    },

    // Overrides to prevent unused import removal inside `overrides.ts` and enums files (for TSDoc linkcodes),
    // as well as in all TS files in `scripts/` (which are assumed to be boilerplate templates).
    {
      "includes": ["**/src/overrides.ts", "**/src/enums/**/*", "**/scripts/**/*.ts", "**/*.d.ts"],
      "linter": {
        "rules": {
          "correctness": {
            "noUnusedImports": "off"
          }
        }
      }
    },
    {
      "includes": ["**/src/overrides.ts", "**/scripts/**/*.ts"],
      "linter": {
        "rules": {
          "style": {
            "useImportType": "off"
          }
        }
      }
    }
  ]
}