no-inferrable-types rule doesn't detect Infinity as an inferrable numeric literal

[mindjuice]

Bug Report

The no-inferrable-types rule should trigger if a variable is assigned the value of Infinity (or -Infinity).

The line in the link below is where the rule checks for a ts.SyntaxKind.NumericLiteral. I took a quick look through the TS code, but wasn't able to find how Infinity is handled. It doesn't seem to be included as a ts.SyntaxKind.NumericLiteral (or this rule would work), nor does there seem to be a ts.SyntaxKind.InfinityKeyword.

https://github.com/palantir/tslint/blob/master/src/rules/noInferrableTypesRule.ts#L112

• TSLint version: 4.5.1
• TypeScript version: 2.3
• Running TSLint via: VSCode

TypeScript code being linted

let foo: number = Infinity

with tslint.json configuration:

{
    "extends": ["tslint-react"],
    "rules": {
        "align": [
            true,
            "parameters",
            "arguments",
            "statements"
        ],
        "array-type": [true, "array"],
        "arrow-return-shorthand": [true, "multiline"],
        "ban": false,
        "class-name": true,
        "comment-format": [
            true,
            "check-space"
        ],
        "curly": true,
        "forin": true,
        "import-spacing": true,
        "indent": [ true, "spaces" ],
        "interface-name": [true, "never-prefix"],
        "jsdoc-format": true,
        "jsx-no-lambda": false,
        "jsx-no-multiline-js": false,
        "label-position": true,
        "max-line-length": [ true, 120 ],
        "member-ordering": [
            true,
            "public-before-private",
            "static-before-instance",
            "variables-before-functions"
        ],
        "new-parens": true,
        "no-angle-bracket-type-assertion": true,
        "no-arg": true,
        "no-bitwise": true,
        "no-conditional-assignment": true,
        "no-console": [
            true,
            "log",
            "error",
            "debug",
            "info",
            "time",
            "timeEnd",
            "trace"
        ],
        "no-consecutive-blank-lines": [true],
        "no-construct": true,
        "no-debugger": true,
        "no-duplicate-super": true,
        "no-duplicate-variable": true,
        "no-empty": true,
        "no-eval": true,
        "no-inferrable-types": [true, "ignore-params"],
        "no-invalid-template-strings": true,
        "no-invalid-this": [true, "check-function-in-method"],
        "no-irregular-whitespace": true,
        "no-misused-new": true,
        "no-null-keyword": true,
        "no-shadowed-variable": true,
        "no-string-literal": true,
        "no-switch-case-fall-through": true,
        "no-trailing-whitespace": true,
        "no-unnecessary-callback-wrapper": true,
        "no-unused-expression": true,
        "no-var-keyword": true,
        "number-literal-format": true,
        "eofline": true,
        "object-literal-key-quotes": [true, "as-needed"],
        "object-literal-shorthand": true,
        "one-line": [
            true,
            "check-catch",
            "check-else",
            "check-open-brace",
            "check-whitespace"
        ],
        "one-variable-per-declaration": [true, "ignore-for-loop"],
        "ordered-imports": [
            true,
            {
                "import-sources-order": "lowercase-last",
                "named-imports-order": "lowercase-first"
            }
        ],
        "prefer-const": true,
        "prefer-for-of": true,
        "prefer-function-over-method": true,
        "prefer-switch": ["true", { "min-cases": 2 }],
        "quotemark": [true, "single"],
        "radix": true,
        "semicolon": [true, "never"],
        "space-before-function-paren": [true, "never"],
        "switch-default": true,
        "trailing-comma": [true, {"multiline": "always", "singleline": "never"}],
        "triple-equals": [ true, "allow-null-check" ],
        "typedef": [
            true,
            "parameter",
            "property-declaration"
        ],
        "typedef-whitespace": [
            true,
            {
                "call-signature": "nospace",
                "index-signature": "nospace",
                "parameter": "nospace",
                "property-declaration": "nospace",
                "variable-declaration": "nospace"
            }
        ],
        "variable-name": [true, "ban-keywords", "check-format", "allow-leading-underscore", "allow-pascal-case"],
        "whitespace": [
            true,
            "check-branch",
            "check-decl",
            "check-module",
            "check-operator",
            "check-separator",
            "check-type",
            "check-typecast"
        ]
    }
}

Actual behavior

The no-inferrable-types message is not shown

Expected behavior

The no-inferrable-types message is shown

[adidahiya]

Can you try and reproduce this bug with the latest TSLint please?

[mindjuice]

Sorry about that.

I've just confirmed that the same bug occurs in v5.2.0.