Files
Tiber365/node_modules/restructure/test/Pointer.js
2025-07-24 18:46:24 +02:00

290 lines
9.5 KiB
JavaScript

import assert from 'assert';
import {Pointer, VoidPointer, uint8, DecodeStream, EncodeStream, Struct} from 'restructure';
describe('Pointer', function() {
describe('decode', function() {
it('should handle null pointers', function() {
const stream = new DecodeStream(new Uint8Array([0]));
const pointer = new Pointer(uint8, uint8);
return assert.equal(pointer.decode(stream, {_startOffset: 50}), null);
});
it('should use local offsets from start of parent by default', function() {
const stream = new DecodeStream(new Uint8Array([1, 53]));
const pointer = new Pointer(uint8, uint8);
assert.equal(pointer.decode(stream, {_startOffset: 0}), 53);
});
it('should support immediate offsets', function() {
const stream = new DecodeStream(new Uint8Array([1, 53]));
const pointer = new Pointer(uint8, uint8, {type: 'immediate'});
assert.equal(pointer.decode(stream), 53);
});
it('should support offsets relative to the parent', function() {
const stream = new DecodeStream(new Uint8Array([0, 0, 1, 53]));
stream.pos = 2;
const pointer = new Pointer(uint8, uint8, {type: 'parent'});
assert.equal(pointer.decode(stream, {parent: {_startOffset: 2}}), 53);
});
it('should support global offsets', function() {
const stream = new DecodeStream(new Uint8Array([1, 2, 4, 0, 0, 0, 53]));
const pointer = new Pointer(uint8, uint8, {type: 'global'});
stream.pos = 2;
assert.equal(pointer.decode(stream, {parent: {parent: {_startOffset: 2}}}), 53);
});
it('should support offsets relative to a property on the parent', function() {
const stream = new DecodeStream(new Uint8Array([1, 0, 0, 0, 0, 53]));
const pointer = new Pointer(uint8, uint8, {relativeTo: ctx => ctx.parent.ptr});
assert.equal(pointer.decode(stream, {_startOffset: 0, parent: {ptr: 4}}), 53);
});
it('should throw when passing a non function relativeTo option', function() {
return assert.throws(() => new Pointer(uint8, uint8, {relativeTo: 'parent.ptr'}));
});
it('should support returning pointer if there is no decode type', function() {
const stream = new DecodeStream(new Uint8Array([4]));
const pointer = new Pointer(uint8, 'void');
assert.equal(pointer.decode(stream, {_startOffset: 0}), 4);
});
it('should support decoding pointers lazily', function() {
const stream = new DecodeStream(new Uint8Array([1, 53]));
const struct = new Struct({
ptr: new Pointer(uint8, uint8, {lazy: true})});
const res = struct.decode(stream);
assert.equal(typeof Object.getOwnPropertyDescriptor(res, 'ptr').get, 'function');
assert.equal(Object.getOwnPropertyDescriptor(res, 'ptr').enumerable, true);
assert.equal(res.ptr, 53);
});
});
describe('size', function() {
it('should add to local pointerSize', function() {
const pointer = new Pointer(uint8, uint8);
const ctx = {pointerSize: 0};
assert.equal(pointer.size(10, ctx), 1);
assert.equal(ctx.pointerSize, 1);
});
it('should add to immediate pointerSize', function() {
const pointer = new Pointer(uint8, uint8, {type: 'immediate'});
const ctx = {pointerSize: 0};
assert.equal(pointer.size(10, ctx), 1);
assert.equal(ctx.pointerSize, 1);
});
it('should add to parent pointerSize', function() {
const pointer = new Pointer(uint8, uint8, {type: 'parent'});
const ctx = {parent: {pointerSize: 0}};
assert.equal(pointer.size(10, ctx), 1);
assert.equal(ctx.parent.pointerSize, 1);
});
it('should add to global pointerSize', function() {
const pointer = new Pointer(uint8, uint8, {type: 'global'});
const ctx = {parent: {parent: {parent: {pointerSize: 0}}}};
assert.equal(pointer.size(10, ctx), 1);
assert.equal(ctx.parent.parent.parent.pointerSize, 1);
});
it('should handle void pointers', function() {
const pointer = new Pointer(uint8, 'void');
const ctx = {pointerSize: 0};
assert.equal(pointer.size(new VoidPointer(uint8, 50), ctx), 1);
assert.equal(ctx.pointerSize, 1);
});
it('should throw if no type and not a void pointer', function() {
const pointer = new Pointer(uint8, 'void');
const ctx = {pointerSize: 0};
assert.throws(() => pointer.size(30, ctx));
});
it('should return a fixed size without a value', function() {
const pointer = new Pointer(uint8, uint8);
assert.equal(pointer.size(), 1);
});
});
describe('encode', function() {
it('should handle null pointers', function() {
const ptr = new Pointer(uint8, uint8);
const ctx = {
pointerSize: 0,
startOffset: 0,
pointerOffset: 0,
pointers: []
};
const stream = new EncodeStream(new Uint8Array(ptr.size(null)));
ptr.encode(stream, null, ctx);
assert.equal(ctx.pointerSize, 0);
assert.deepEqual(stream.buffer, new Uint8Array([0]));
});
it('should handle local offsets', function() {
const ptr = new Pointer(uint8, uint8);
const ctx = {
pointerSize: 0,
startOffset: 0,
pointerOffset: 1,
pointers: []
};
const stream = new EncodeStream(new Uint8Array(ptr.size(10)));
ptr.encode(stream, 10, ctx);
assert.equal(ctx.pointerOffset, 2);
assert.deepEqual(ctx.pointers, [
{ type: uint8, val: 10, parent: ctx }
]);
assert.deepEqual(stream.buffer, new Uint8Array([1]));
});
it('should handle immediate offsets', function() {
const ptr = new Pointer(uint8, uint8, {type: 'immediate'});
const ctx = {
pointerSize: 0,
startOffset: 0,
pointerOffset: 1,
pointers: []
};
const stream = new EncodeStream(new Uint8Array(ptr.size(10)));
ptr.encode(stream, 10, ctx);
assert.equal(ctx.pointerOffset, 2);
assert.deepEqual(ctx.pointers, [
{ type: uint8, val: 10, parent: ctx }
]);
assert.deepEqual(stream.buffer, new Uint8Array([0]));
});
it('should handle immediate offsets', function() {
const ptr = new Pointer(uint8, uint8, {type: 'immediate'});
const ctx = {
pointerSize: 0,
startOffset: 0,
pointerOffset: 1,
pointers: []
};
const stream = new EncodeStream(new Uint8Array(ptr.size(10)));
ptr.encode(stream, 10, ctx);
assert.equal(ctx.pointerOffset, 2);
assert.deepEqual(ctx.pointers, [
{ type: uint8, val: 10, parent: ctx }
]);
assert.deepEqual(stream.buffer, new Uint8Array([0]));
});
it('should handle offsets relative to parent', function() {
const ptr = new Pointer(uint8, uint8, {type: 'parent'});
const ctx = {
parent: {
pointerSize: 0,
startOffset: 3,
pointerOffset: 5,
pointers: []
}
};
const stream = new EncodeStream(new Uint8Array(ptr.size(10, {parent: {...ctx.parent}})));
ptr.encode(stream, 10, ctx);
assert.equal(ctx.parent.pointerOffset, 6);
assert.deepEqual(ctx.parent.pointers, [
{ type: uint8, val: 10, parent: ctx }
]);
assert.deepEqual(stream.buffer, new Uint8Array([2]));
});
it('should handle global offsets', function() {
const ptr = new Pointer(uint8, uint8, {type: 'global'});
const ctx = {
parent: {
parent: {
parent: {
pointerSize: 0,
startOffset: 3,
pointerOffset: 5,
pointers: []
}
}
}
};
const stream = new EncodeStream(new Uint8Array(ptr.size(10, JSON.parse(JSON.stringify(ctx)))));
ptr.encode(stream, 10, ctx);
assert.equal(ctx.parent.parent.parent.pointerOffset, 6);
assert.deepEqual(ctx.parent.parent.parent.pointers, [
{ type: uint8, val: 10, parent: ctx }
]);
assert.deepEqual(stream.buffer, new Uint8Array([5]));
});
it('should support offsets relative to a property on the parent', function() {
const ptr = new Pointer(uint8, uint8, {relativeTo: ctx => ctx.ptr});
const ctx = {
pointerSize: 0,
startOffset: 0,
pointerOffset: 10,
pointers: [],
val: {
ptr: 4
}
};
const stream = new EncodeStream(new Uint8Array(ptr.size(10, {...ctx})));
ptr.encode(stream, 10, ctx);
assert.equal(ctx.pointerOffset, 11);
assert.deepEqual(ctx.pointers, [
{ type: uint8, val: 10, parent: ctx }
]);
assert.deepEqual(stream.buffer, new Uint8Array([6]));
});
it('should support void pointers', function() {
const ptr = new Pointer(uint8, 'void');
const ctx = {
pointerSize: 0,
startOffset: 0,
pointerOffset: 1,
pointers: []
};
const val = new VoidPointer(uint8, 55);
const stream = new EncodeStream(new Uint8Array(ptr.size(val, {...ctx})));
ptr.encode(stream, val, ctx);
assert.equal(ctx.pointerOffset, 2);
assert.deepEqual(ctx.pointers, [
{ type: uint8, val: 55, parent: ctx }
]);
assert.deepEqual(stream.buffer, new Uint8Array([1]));
});
it('should throw if not a void pointer instance', function() {
const ptr = new Pointer(uint8, 'void');
const ctx = {
pointerSize: 0,
startOffset: 0,
pointerOffset: 1,
pointers: []
};
const stream = new EncodeStream(new Uint8Array(0));
assert.throws(() => ptr.encode(stream, 44, ctx));
});
});
});