excalidraw/excalidraw-app/tests/reconciliation.test.ts

422 lines
12 KiB
TypeScript

import { expect } from "chai";
import { PRECEDING_ELEMENT_KEY } from "../../packages/excalidraw/constants";
import { ExcalidrawElement } from "../../packages/excalidraw/element/types";
import {
BroadcastedExcalidrawElement,
ReconciledElements,
reconcileElements,
} from "../../excalidraw-app/collab/reconciliation";
import { randomInteger } from "../../packages/excalidraw/random";
import { AppState } from "../../packages/excalidraw/types";
import { cloneJSON } from "../../packages/excalidraw/utils";
type Id = string;
type ElementLike = {
id: string;
version: number;
versionNonce: number;
[PRECEDING_ELEMENT_KEY]?: string | null;
};
type Cache = Record<string, ExcalidrawElement | undefined>;
const createElement = (opts: { uid: string } | ElementLike) => {
let uid: string;
let id: string;
let version: number | null;
let parent: string | null = null;
let versionNonce: number | null = null;
if ("uid" in opts) {
const match = opts.uid.match(
/^(?:\((\^|\w+)\))?(\w+)(?::(\d+))?(?:\((\w+)\))?$/,
)!;
parent = match[1];
id = match[2];
version = match[3] ? parseInt(match[3]) : null;
uid = version ? `${id}:${version}` : id;
} else {
({ id, version, versionNonce } = opts);
parent = parent || null;
uid = id;
}
return {
uid,
id,
version,
versionNonce: versionNonce || randomInteger(),
[PRECEDING_ELEMENT_KEY]: parent || null,
};
};
const idsToElements = (
ids: (Id | ElementLike)[],
cache: Cache = {},
): readonly ExcalidrawElement[] => {
return ids.reduce((acc, _uid, idx) => {
const {
uid,
id,
version,
[PRECEDING_ELEMENT_KEY]: parent,
versionNonce,
} = createElement(typeof _uid === "string" ? { uid: _uid } : _uid);
const cached = cache[uid];
const elem = {
id,
version: version ?? 0,
versionNonce,
...cached,
[PRECEDING_ELEMENT_KEY]: parent,
} as BroadcastedExcalidrawElement;
// @ts-ignore
cache[uid] = elem;
acc.push(elem);
return acc;
}, [] as ExcalidrawElement[]);
};
const addParents = (elements: BroadcastedExcalidrawElement[]) => {
return elements.map((el, idx, els) => {
el[PRECEDING_ELEMENT_KEY] = els[idx - 1]?.id || "^";
return el;
});
};
const cleanElements = (elements: ReconciledElements) => {
return elements.map((el) => {
// @ts-ignore
delete el[PRECEDING_ELEMENT_KEY];
// @ts-ignore
delete el.next;
// @ts-ignore
delete el.prev;
return el;
});
};
const test = <U extends `${string}:${"L" | "R"}`>(
local: (Id | ElementLike)[],
remote: (Id | ElementLike)[],
target: U[],
bidirectional = true,
) => {
const cache: Cache = {};
const _local = idsToElements(local, cache);
const _remote = idsToElements(remote, cache);
const _target = target.map((uid) => {
const [, id, source] = uid.match(/^(\w+):([LR])$/)!;
return (source === "L" ? _local : _remote).find((e) => e.id === id)!;
}) as any as ReconciledElements;
const remoteReconciled = reconcileElements(_local, _remote, {} as AppState);
expect(target.length).equal(remoteReconciled.length);
expect(cleanElements(remoteReconciled)).deep.equal(
cleanElements(_target),
"remote reconciliation",
);
const __local = cleanElements(cloneJSON(_remote) as ReconciledElements);
const __remote = addParents(cleanElements(cloneJSON(remoteReconciled)));
if (bidirectional) {
try {
expect(
cleanElements(
reconcileElements(
cloneJSON(__local),
cloneJSON(__remote),
{} as AppState,
),
),
).deep.equal(cleanElements(remoteReconciled), "local re-reconciliation");
} catch (error: any) {
console.error("local original", __local);
console.error("remote reconciled", __remote);
throw error;
}
}
};
export const findIndex = <T>(
array: readonly T[],
cb: (element: T, index: number, array: readonly T[]) => boolean,
fromIndex: number = 0,
) => {
if (fromIndex < 0) {
fromIndex = array.length + fromIndex;
}
fromIndex = Math.min(array.length, Math.max(fromIndex, 0));
let index = fromIndex - 1;
while (++index < array.length) {
if (cb(array[index], index, array)) {
return index;
}
}
return -1;
};
// -----------------------------------------------------------------------------
describe("elements reconciliation", () => {
it("reconcileElements()", () => {
// -------------------------------------------------------------------------
//
// in following tests, we pass:
// (1) an array of local elements and their version (:1, :2...)
// (2) an array of remote elements and their version (:1, :2...)
// (3) expected reconciled elements
//
// in the reconciled array:
// :L means local element was resolved
// :R means remote element was resolved
//
// if a remote element is prefixed with parentheses, the enclosed string:
// (^) means the element is the first element in the array
// (<id>) means the element is preceded by <id> element
//
// if versions are missing, it defaults to version 0
// -------------------------------------------------------------------------
// non-annotated elements
// -------------------------------------------------------------------------
// usually when we sync elements they should always be annotated with
// their (preceding elements) parents, but let's test a couple of cases when
// they're not for whatever reason (remote clients are on older version...),
// in which case the first synced element either replaces existing element
// or is pushed at the end of the array
test(["A:1", "B:1", "C:1"], ["B:2"], ["A:L", "B:R", "C:L"]);
test(["A:1", "B:1", "C"], ["B:2", "A:2"], ["B:R", "A:R", "C:L"]);
test(["A:2", "B:1", "C"], ["B:2", "A:1"], ["A:L", "B:R", "C:L"]);
test(["A:1", "B:1"], ["C:1"], ["A:L", "B:L", "C:R"]);
test(["A", "B"], ["A:1"], ["A:R", "B:L"]);
test(["A"], ["A", "B"], ["A:L", "B:R"]);
test(["A"], ["A:1", "B"], ["A:R", "B:R"]);
test(["A:2"], ["A:1", "B"], ["A:L", "B:R"]);
test(["A:2"], ["B", "A:1"], ["A:L", "B:R"]);
test(["A:1"], ["B", "A:2"], ["B:R", "A:R"]);
test(["A"], ["A:1"], ["A:R"]);
// C isn't added to the end because it follows B (even if B was resolved
// to local version)
test(["A", "B:1", "D"], ["B", "C:2", "A"], ["B:L", "C:R", "A:R", "D:L"]);
// some of the following tests are kinda arbitrary and they're less
// likely to happen in real-world cases
test(["A", "B"], ["B:1", "A:1"], ["B:R", "A:R"]);
test(["A:2", "B:2"], ["B:1", "A:1"], ["A:L", "B:L"]);
test(["A", "B", "C"], ["A", "B:2", "G", "C"], ["A:L", "B:R", "G:R", "C:L"]);
test(["A", "B", "C"], ["A", "B:2", "G"], ["A:L", "B:R", "G:R", "C:L"]);
test(["A", "B", "C"], ["A", "B:2", "G"], ["A:L", "B:R", "G:R", "C:L"]);
test(
["A:2", "B:2", "C"],
["D", "B:1", "A:3"],
["B:L", "A:R", "C:L", "D:R"],
);
test(
["A:2", "B:2", "C"],
["D", "B:2", "A:3", "C"],
["D:R", "B:L", "A:R", "C:L"],
);
test(
["A", "B", "C", "D", "E", "F"],
["A", "B:2", "X", "E:2", "F", "Y"],
["A:L", "B:R", "X:R", "E:R", "F:L", "Y:R", "C:L", "D:L"],
);
// annotated elements
// -------------------------------------------------------------------------
test(
["A", "B", "C"],
["(B)X", "(A)Y", "(Y)Z"],
["A:L", "B:L", "X:R", "Y:R", "Z:R", "C:L"],
);
test(["A"], ["(^)X", "Y"], ["X:R", "Y:R", "A:L"]);
test(["A"], ["(^)X", "Y", "Z"], ["X:R", "Y:R", "Z:R", "A:L"]);
test(
["A", "B"],
["(A)C", "(^)D", "F"],
["A:L", "C:R", "D:R", "F:R", "B:L"],
);
test(
["A", "B", "C", "D"],
["(B)C:1", "B", "D:1"],
["A:L", "C:R", "B:L", "D:R"],
);
test(
["A", "B", "C"],
["(^)X", "(A)Y", "(B)Z"],
["X:R", "A:L", "Y:R", "B:L", "Z:R", "C:L"],
);
test(
["B", "A", "C"],
["(^)X", "(A)Y", "(B)Z"],
["X:R", "B:L", "A:L", "Y:R", "Z:R", "C:L"],
);
test(["A", "B"], ["(A)X", "(A)Y"], ["A:L", "X:R", "Y:R", "B:L"]);
test(
["A", "B", "C", "D", "E"],
["(A)X", "(C)Y", "(D)Z"],
["A:L", "X:R", "B:L", "C:L", "Y:R", "D:L", "Z:R", "E:L"],
);
test(
["X", "Y", "Z"],
["(^)A", "(A)B", "(B)C", "(C)X", "(X)D", "(D)Y", "(Y)Z"],
["A:R", "B:R", "C:R", "X:L", "D:R", "Y:L", "Z:L"],
);
test(
["A", "B", "C", "D", "E"],
["(C)X", "(A)Y", "(D)E:1"],
["A:L", "B:L", "C:L", "X:R", "Y:R", "D:L", "E:R"],
);
test(
["C:1", "B", "D:1"],
["A", "B", "C:1", "D:1"],
["A:R", "B:L", "C:L", "D:L"],
);
test(
["A", "B", "C", "D"],
["(A)C:1", "(C)B", "(B)D:1"],
["A:L", "C:R", "B:L", "D:R"],
);
test(
["A", "B", "C", "D"],
["(A)C:1", "(C)B", "(B)D:1"],
["A:L", "C:R", "B:L", "D:R"],
);
test(
["C:1", "B", "D:1"],
["(^)A", "(A)B", "(B)C:2", "(C)D:1"],
["A:R", "B:L", "C:R", "D:L"],
);
test(
["A", "B", "C", "D"],
["(C)X", "(B)Y", "(A)Z"],
["A:L", "B:L", "C:L", "X:R", "Y:R", "Z:R", "D:L"],
);
test(["A", "B", "C", "D"], ["(A)B:1", "C:1"], ["A:L", "B:R", "C:R", "D:L"]);
test(["A", "B", "C", "D"], ["(A)C:1", "B:1"], ["A:L", "C:R", "B:R", "D:L"]);
test(
["A", "B", "C", "D"],
["(A)C:1", "B", "D:1"],
["A:L", "C:R", "B:L", "D:R"],
);
test(["A:1", "B:1", "C"], ["B:2"], ["A:L", "B:R", "C:L"]);
test(["A:1", "B:1", "C"], ["B:2", "C:2"], ["A:L", "B:R", "C:R"]);
test(["A", "B"], ["(A)C", "(B)D"], ["A:L", "C:R", "B:L", "D:R"]);
test(["A", "B"], ["(X)C", "(X)D"], ["A:L", "B:L", "C:R", "D:R"]);
test(["A", "B"], ["(X)C", "(A)D"], ["A:L", "D:R", "B:L", "C:R"]);
test(["A", "B"], ["(A)B:1"], ["A:L", "B:R"]);
test(["A:2", "B"], ["(A)B:1"], ["A:L", "B:R"]);
test(["A:2", "B:2"], ["B:1"], ["A:L", "B:L"]);
test(["A:2", "B:2"], ["B:1", "C"], ["A:L", "B:L", "C:R"]);
test(["A:2", "B:2"], ["(A)C", "B:1"], ["A:L", "C:R", "B:L"]);
test(["A:2", "B:2"], ["(A)C", "B:1"], ["A:L", "C:R", "B:L"]);
});
it("test identical elements reconciliation", () => {
const testIdentical = (
local: ElementLike[],
remote: ElementLike[],
expected: Id[],
) => {
const ret = reconcileElements(
local as any as ExcalidrawElement[],
remote as any as ExcalidrawElement[],
{} as AppState,
);
if (new Set(ret.map((x) => x.id)).size !== ret.length) {
throw new Error("reconcileElements: duplicate elements found");
}
expect(ret.map((x) => x.id)).to.deep.equal(expected);
};
// identical id/version/versionNonce
// -------------------------------------------------------------------------
testIdentical(
[{ id: "A", version: 1, versionNonce: 1 }],
[{ id: "A", version: 1, versionNonce: 1 }],
["A"],
);
testIdentical(
[
{ id: "A", version: 1, versionNonce: 1 },
{ id: "B", version: 1, versionNonce: 1 },
],
[
{ id: "B", version: 1, versionNonce: 1 },
{ id: "A", version: 1, versionNonce: 1 },
],
["B", "A"],
);
testIdentical(
[
{ id: "A", version: 1, versionNonce: 1 },
{ id: "B", version: 1, versionNonce: 1 },
],
[
{ id: "B", version: 1, versionNonce: 1 },
{ id: "A", version: 1, versionNonce: 1 },
],
["B", "A"],
);
// actually identical (arrays and element objects)
// -------------------------------------------------------------------------
const elements1 = [
{
id: "A",
version: 1,
versionNonce: 1,
[PRECEDING_ELEMENT_KEY]: null,
},
{
id: "B",
version: 1,
versionNonce: 1,
[PRECEDING_ELEMENT_KEY]: null,
},
];
testIdentical(elements1, elements1, ["A", "B"]);
testIdentical(elements1, elements1.slice(), ["A", "B"]);
testIdentical(elements1.slice(), elements1, ["A", "B"]);
testIdentical(elements1.slice(), elements1.slice(), ["A", "B"]);
const el1 = {
id: "A",
version: 1,
versionNonce: 1,
[PRECEDING_ELEMENT_KEY]: null,
};
const el2 = {
id: "B",
version: 1,
versionNonce: 1,
[PRECEDING_ELEMENT_KEY]: null,
};
testIdentical([el1, el2], [el2, el1], ["A", "B"]);
});
});