Extend JavaScript ast-grep rules to match functions/methods in pairs and objects

[jy-tan]

Context

Previously, the function rules for JS wouldn't match these functions and methods:

// Property identifier in a 'pair' with a 'function_expression'
const objWithFuncExpr = {
  propFuncExpr: function () {
    console.log("Hello, world!");
  },
};

// Property identifier in a 'method_definition' (object shorthand method)
const objWithShorthand = {
  shorthandObjMethod() {},

  *generatorShorthandMethod() {},

  async asyncShorthandMethod() {},
};

Changes

• Include matches for function_expression in pair and method_definition in property_identifier
• Add tests