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std/fs/ensure_symlink.ts

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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.import { dirname } from "../path/dirname.ts";import { resolve } from "../path/resolve.ts";import { ensureDir, ensureDirSync } from "./ensure_dir.ts";import { getFileInfoType } from "./_get_file_info_type.ts";import { toPathString } from "./_to_path_string.ts";
const isWindows = Deno.build.os === "windows";
function resolveSymlinkTarget(target: string | URL, linkName: string | URL) { if (typeof target !== "string") return target; // URL is always absolute path if (typeof linkName === "string") { return resolve(dirname(linkName), target); } else { return new URL(target, linkName); }}
/** * Ensures that the link exists, and points to a valid file. * If the directory structure does not exist, it is created. * If the link already exists, it is not modified but error is thrown if it is not point to the given target. * Requires the `--allow-read` and `--allow-write` flag. * * @param target the source file path * @param linkName the destination link path */export async function ensureSymlink( target: string | URL, linkName: string | URL,) { const targetRealPath = resolveSymlinkTarget(target, linkName); const srcStatInfo = await Deno.lstat(targetRealPath); const srcFilePathType = getFileInfoType(srcStatInfo);
await ensureDir(dirname(toPathString(linkName)));
const options: Deno.SymlinkOptions | undefined = isWindows ? { type: srcFilePathType === "dir" ? "dir" : "file", } : undefined;
try { await Deno.symlink(target, linkName, options); } catch (error) { if (!(error instanceof Deno.errors.AlreadyExists)) { throw error; } const linkStatInfo = await Deno.lstat(linkName); if (!linkStatInfo.isSymlink) { const type = getFileInfoType(linkStatInfo); throw new Deno.errors.AlreadyExists( `A '${type}' already exists at the path: ${linkName}`, ); } const linkPath = await Deno.readLink(linkName); const linkRealPath = resolve(linkPath); if (linkRealPath !== targetRealPath) { throw new Deno.errors.AlreadyExists( `A symlink targeting to an undesired path already exists: ${linkName} -> ${linkRealPath}`, ); } }}
/** * Ensures that the link exists, and points to a valid file. * If the directory structure does not exist, it is created. * If the link already exists, it is not modified but error is thrown if it is not point to the given target. * Requires the `--allow-read` and `--allow-write` flag. * * @param target the source file path * @param linkName the destination link path */export function ensureSymlinkSync( target: string | URL, linkName: string | URL,) { const targetRealPath = resolveSymlinkTarget(target, linkName); const srcStatInfo = Deno.lstatSync(targetRealPath); const srcFilePathType = getFileInfoType(srcStatInfo);
ensureDirSync(dirname(toPathString(linkName)));
const options: Deno.SymlinkOptions | undefined = isWindows ? { type: srcFilePathType === "dir" ? "dir" : "file", } : undefined;
try { Deno.symlinkSync(target, linkName, options); } catch (error) { if (!(error instanceof Deno.errors.AlreadyExists)) { throw error; } const linkStatInfo = Deno.lstatSync(linkName); if (!linkStatInfo.isSymlink) { const type = getFileInfoType(linkStatInfo); throw new Deno.errors.AlreadyExists( `A '${type}' already exists at the path: ${linkName}`, ); } const linkPath = Deno.readLinkSync(linkName); const linkRealPath = resolve(linkPath); if (linkRealPath !== targetRealPath) { throw new Deno.errors.AlreadyExists( `A symlink targeting to an undesired path already exists: ${linkName} -> ${linkRealPath}`, ); } }}