Mario Romano 29df96a085 react app
2016-04-06 17:52:19 +01:00

208 lines
6.2 KiB
JavaScript

"use strict";
var _interopRequireWildcard = require("babel-runtime/helpers/interop-require-wildcard")["default"];
exports.__esModule = true;
var _babelTypes = require("babel-types");
var t = _interopRequireWildcard(_babelTypes);
exports["default"] = function (node) {
if (!this.isReferenced()) return;
// check if a binding exists of this value and if so then return a union type of all
// possible types that the binding could be
var binding = this.scope.getBinding(node.name);
if (binding) {
if (binding.identifier.typeAnnotation) {
return binding.identifier.typeAnnotation;
} else {
return getTypeAnnotationBindingConstantViolations(this, node.name);
}
}
// built-in values
if (node.name === "undefined") {
return t.voidTypeAnnotation();
} else if (node.name === "NaN" || node.name === "Infinity") {
return t.numberTypeAnnotation();
} else if (node.name === "arguments") {
// todo
}
};
function getTypeAnnotationBindingConstantViolations(path, name) {
var binding = path.scope.getBinding(name);
var types = [];
path.typeAnnotation = t.unionTypeAnnotation(types);
var functionConstantViolations = [];
var constantViolations = getConstantViolationsBefore(binding, path, functionConstantViolations);
var testType = getConditionalAnnotation(path, name);
if (testType) {
(function () {
var testConstantViolations = getConstantViolationsBefore(binding, testType.ifStatement);
// remove constant violations observed before the IfStatement
constantViolations = constantViolations.filter(function (path) {
return testConstantViolations.indexOf(path) < 0;
});
// clear current types and add in observed test type
types.push(testType.typeAnnotation);
})();
}
if (constantViolations.length) {
// pick one constant from each scope which will represent the last possible
// control flow path that it could've taken/been
/* This code is broken for the following problems:
* It thinks that assignments can only happen in scopes.
* What about conditionals, if statements without block,
* or guarded assignments.
* It also checks to see if one of the assignments is in the
* same scope and uses that as the only "violation". However,
* the binding is returned by `getConstantViolationsBefore` so we for
* sure always going to return that as the only "violation".
let rawConstantViolations = constantViolations.reverse();
let visitedScopes = [];
constantViolations = [];
for (let violation of (rawConstantViolations: Array<NodePath>)) {
let violationScope = violation.scope;
if (visitedScopes.indexOf(violationScope) >= 0) continue;
visitedScopes.push(violationScope);
constantViolations.push(violation);
if (violationScope === path.scope) {
constantViolations = [violation];
break;
}
}*/
// add back on function constant violations since we can't track calls
constantViolations = constantViolations.concat(functionConstantViolations);
// push on inferred types of violated paths
var _arr = constantViolations;
for (var _i = 0; _i < _arr.length; _i++) {
var violation = _arr[_i];
types.push(violation.getTypeAnnotation());
}
}
if (types.length) {
return t.createUnionTypeAnnotation(types);
}
}
function getConstantViolationsBefore(binding, path, functions) {
var violations = binding.constantViolations.slice();
violations.unshift(binding.path);
return violations.filter(function (violation) {
violation = violation.resolve();
var status = violation._guessExecutionStatusRelativeTo(path);
if (functions && status === "function") functions.push(violation);
return status === "before";
});
}
function inferAnnotationFromBinaryExpression(name, path) {
var operator = path.node.operator;
var right = path.get("right").resolve();
var left = path.get("left").resolve();
var target = undefined;
if (left.isIdentifier({ name: name })) {
target = right;
} else if (right.isIdentifier({ name: name })) {
target = left;
}
if (target) {
if (operator === "===") {
return target.getTypeAnnotation();
} else if (t.BOOLEAN_NUMBER_BINARY_OPERATORS.indexOf(operator) >= 0) {
return t.numberTypeAnnotation();
} else {
return;
}
} else {
if (operator !== "===") return;
}
//
var typeofPath = undefined;
var typePath = undefined;
if (left.isUnaryExpression({ operator: "typeof" })) {
typeofPath = left;
typePath = right;
} else if (right.isUnaryExpression({ operator: "typeof" })) {
typeofPath = right;
typePath = left;
}
if (!typePath && !typeofPath) return;
// ensure that the type path is a Literal
typePath = typePath.resolve();
if (!typePath.isLiteral()) return;
// and that it's a string so we can infer it
var typeValue = typePath.node.value;
if (typeof typeValue !== "string") return;
// and that the argument of the typeof path references us!
if (!typeofPath.get("argument").isIdentifier({ name: name })) return;
// turn type value into a type annotation
return t.createTypeAnnotationBasedOnTypeof(typePath.node.value);
}
function getParentConditionalPath(path) {
var parentPath = undefined;
while (parentPath = path.parentPath) {
if (parentPath.isIfStatement() || parentPath.isConditionalExpression()) {
if (path.key === "test") {
return;
} else {
return parentPath;
}
} else {
path = parentPath;
}
}
}
function getConditionalAnnotation(path, name) {
var ifStatement = getParentConditionalPath(path);
if (!ifStatement) return;
var test = ifStatement.get("test");
var paths = [test];
var types = [];
do {
var _path = paths.shift().resolve();
if (_path.isLogicalExpression()) {
paths.push(_path.get("left"));
paths.push(_path.get("right"));
}
if (_path.isBinaryExpression()) {
var type = inferAnnotationFromBinaryExpression(name, _path);
if (type) types.push(type);
}
} while (paths.length);
if (types.length) {
return {
typeAnnotation: t.createUnionTypeAnnotation(types),
ifStatement: ifStatement
};
} else {
return getConditionalAnnotation(ifStatement, name);
}
}
module.exports = exports["default"];