Function getRecursionIdentity

test/fixtures/snapshot/typescript.js:67210–67244

(type)

        // identity of the type, meaning that every type is unique. Generally, types with constituents that could circularly
        // reference the type have a recursion identity that differs from the object identity.
        function getRecursionIdentity(type) {
            // Object and array literals are known not to contain recursive references and don't need a recursion identity.
            if (type.flags & 524288 /* TypeFlags.Object */ && !isObjectOrArrayLiteralType(type)) {
                if (ts.getObjectFlags(type) && 4 /* ObjectFlags.Reference */ && type.node) {
                    // Deferred type references are tracked through their associated AST node. This gives us finer
                    // granularity than using their associated target because each manifest type reference has a
                    // unique AST node.
                    return type.node;
                }
                if (type.symbol && !(ts.getObjectFlags(type) & 16 /* ObjectFlags.Anonymous */ && type.symbol.flags & 32 /* SymbolFlags.Class */)) {
                    // We track all object types that have an associated symbol (representing the origin of the type), but
                    // exclude the static side of classes from this check since it shares its symbol with the instance side.
                    return type.symbol;
                }
                if (isTupleType(type)) {
                    // Tuple types are tracked through their target type
                    return type.target;
                }
            }
            if (type.flags & 262144 /* TypeFlags.TypeParameter */) {
                return type.symbol;
            }
            if (type.flags & 8388608 /* TypeFlags.IndexedAccess */) {
                // Identity is the leftmost object type in a chain of indexed accesses, eg, in A[P][Q] it is A
                do {
                    type = type.objectType;
                } while (type.flags & 8388608 /* TypeFlags.IndexedAccess */);
                return type;
            }
            if (type.flags & 16777216 /* TypeFlags.Conditional */) {
                // The root object represents the origin of the conditional type
                return type.root;
            }
            return type;
        }
        function isPropertyIdenticalTo(sourceProp, targetProp) {
            return compareProperties(sourceProp, targetProp, compareTypesIdentical) !== 0 /* Ternary.False */;
        }