eslintrc.flow

// Flow static typing lint rules
// https://github.com/gajus/eslint-plugin-flowtype
// https://flowtype.org/
{
    "rules": {
        "flowtype/boolean-style": [2, "boolean"],
        "flowtype/define-flow-type": 1, // suppress no-undef on flow types
        "flowtype/no-dupe-keys": 2,

        // Use Flow's version of no-unused-expressions
        "flowtype/no-unused-expressions": [2, {"allowShortCircuit": true, "allowTernary": true}],
        "no-unused-expressions": 0, // Disable this rule as flowtype/no-unused-expression supersedes it

        "flowtype/no-weak-types": 0,    // allow 'any' for now
        // flow may still require parameter types in certain situations
        "flowtype/require-parameter-type": 0,
        "flowtype/require-return-type": 0,
        "flowtype/require-valid-file-annotation": [
            2,
            "always", {
                "annotationStyle": "line"
            }
        ],
        "flowtype/sort": 0,
        "flowtype/type-id-match": 0,
        "flowtype/use-flow-type": 1,  // suppress no-unused-vars on flow types
    },
    "settings": {
        "flowtype": {
            "onlyFilesWithFlowAnnotation": true
        }
    },
    "extends": [
        "prettier/flowtype"
    ],
    "plugins": [
        "flowtype"
    ]
}