import { fromFileUrl, join, parse, toFileUrl } from "../path/mod.ts";import { ensureFile, ensureFileSync } from "../fs/mod.ts";import { bold, green, red } from "../fmt/colors.ts";import { AssertionError, equal } from "./asserts.ts";import { buildMessage, diff, diffstr } from "./_diff.ts";
const CAN_NOT_DISPLAY = "[Cannot display]";const SNAPSHOT_DIR = "__snapshots__";
type AssertSnapshotContext = { snapshotFileUrl: URL | null; teardownRegistered: boolean; currentSnapshot: Map<string, string> | null; updatedSnapshot: Map<string, string>; snapshotCounts: Map<string, number>; snapshotUpdatedCount: number;};
let _assertSnapshotContext: AssertSnapshotContext;
function serialize(actual: unknown): string;function serialize<T>(actual: T): string;function serialize(actual: unknown): string { return Deno.inspect(actual, { depth: Infinity, sorted: true, trailingComma: true, compact: false, iterableLimit: Infinity, strAbbreviateSize: Infinity, });}
function writeSnapshotFileSync(context: AssertSnapshotContext) { const buf = ["export const snapshot = {};"]; function escapeStringForJs(str: string) { return str .replace(/\\/g, "\\\\") .replace(/`/g, "\\`") .replace(/\$/g, "\\$"); } context.updatedSnapshot.forEach((value, key) => { let formattedValue = escapeStringForJs(value); formattedValue = formattedValue.includes("\n") ? `\n${formattedValue}\n` : formattedValue; const formattedKey = escapeStringForJs(key); buf.push(`\nsnapshot[\`${formattedKey}\`] = \`${formattedValue}\`;`); }); const snapshotFilePath = fromFileUrl(context.snapshotFileUrl as URL); ensureFileSync(snapshotFilePath); Deno.writeTextFileSync(snapshotFilePath, buf.join("\n") + "\n");}
function registerSnapshotTeardown(context: AssertSnapshotContext) { if (context.teardownRegistered) return; globalThis.addEventListener("unload", () => { writeSnapshotFileSync(context); if (context.snapshotUpdatedCount > 0) { console.log( green(bold(`\n > ${context.snapshotUpdatedCount} snapshots updated.`)), ); } }); context.teardownRegistered = true;}
export async function assertSnapshot( context: Deno.TestContext, actual: unknown, msg?: string,): Promise<void>;export async function assertSnapshot<T>( context: Deno.TestContext, actual: T, msg?: string,): Promise<void>;export async function assertSnapshot( context: Deno.TestContext, actual: unknown, msg?: string,): Promise<void> { const assertSnapshotContext = getAssertSnapshotContext(); const testName = getTestName(context); const count = getCount(); const snapshotName = `${testName} ${count}`; const snapshotFileUrl = getSnapshotFileUrl(); const isUpdate = Deno.args.some((arg) => arg === "--update" || arg === "-u"); const currentSnapshot = await readSnapshotFile();
const _actual = serialize(actual); const _expected = getExpected(); if (isUpdate) { if (!equal(_actual, _expected)) { assertSnapshotContext.snapshotUpdatedCount++; } assertSnapshotContext.updatedSnapshot.set(snapshotName, _actual); registerSnapshotTeardown(assertSnapshotContext); } else { if (!_expected) { throw new AssertionError(`Missing snapshot: ${snapshotName}`); } if (equal(_actual, _expected)) { return; } let message = ""; try { const stringDiff = (!_actual.includes("\n")) && (!_actual.includes("\n")); const diffResult = stringDiff ? diffstr(_actual, _expected) : diff(_actual.split("\n"), _expected.split("\n")); const diffMsg = buildMessage(diffResult, { stringDiff }).join("\n"); message = `Snapshot does not match:\n${diffMsg}`; } catch { message = `Snapshot does not match:\n${red(CAN_NOT_DISPLAY)} \n\n`; } if (msg) { message = msg; } throw new AssertionError(message); }
function getAssertSnapshotContext() { if (!_assertSnapshotContext) { _assertSnapshotContext = { snapshotFileUrl: null, teardownRegistered: false, currentSnapshot: null, updatedSnapshot: new Map(), snapshotCounts: new Map(), snapshotUpdatedCount: 0, }; } return _assertSnapshotContext; } function getTestName(context: Deno.TestContext): string { if (context.parent) { return `${getTestName(context.parent)} > ${context.name}`; } return context.name; } function getCount() { const count = assertSnapshotContext.snapshotCounts.get(testName) || 1; assertSnapshotContext.snapshotCounts.set(testName, count + 1); return count; } function getSnapshotFileUrl() { if (assertSnapshotContext.snapshotFileUrl) { return assertSnapshotContext.snapshotFileUrl; } const testFile = fromFileUrl(context.origin); const parts = parse(testFile); assertSnapshotContext.snapshotFileUrl = toFileUrl( `${join(parts.dir, SNAPSHOT_DIR, parts.name)}${parts.ext}.snap`, ); return assertSnapshotContext.snapshotFileUrl; } function getExpected() { const snapshot = currentSnapshot.get(snapshotName); if (typeof snapshot === "undefined") { return; } return snapshot.includes("\n") ? snapshot.slice(1, -1) : snapshot; } async function readSnapshotFile() { if (assertSnapshotContext.currentSnapshot) { return assertSnapshotContext.currentSnapshot; } if (isUpdate) { await ensureFile(fromFileUrl(snapshotFileUrl)); } try { const { snapshot } = await import(snapshotFileUrl.toString()); assertSnapshotContext.currentSnapshot = typeof snapshot === "undefined" ? new Map() : new Map(Object.entries(snapshot)); return assertSnapshotContext.currentSnapshot; } catch (error) { if ( error instanceof TypeError && error.message.startsWith("Module not found") ) { throw new AssertionError("Missing snapshot file."); } throw error; } }}