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std/path/posix/parse.ts

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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
import { CHAR_DOT } from "../_common/constants.ts";import type { ParsedPath } from "../_interface.ts";import { stripTrailingSeparators } from "../_common/strip_trailing_separators.ts";import { assertPath } from "../_common/assert_path.ts";import { isPosixPathSeparator } from "./_util.ts";
export type { ParsedPath } from "../_interface.ts";
/** * Return a `ParsedPath` object of the `path`. * @param path to process */export function parse(path: string): ParsedPath { assertPath(path);
const ret: ParsedPath = { root: "", dir: "", base: "", ext: "", name: "" }; if (path.length === 0) return ret; const isAbsolute = isPosixPathSeparator(path.charCodeAt(0)); let start: number; if (isAbsolute) { ret.root = "/"; start = 1; } else { start = 0; } let startDot = -1; let startPart = 0; let end = -1; let matchedSlash = true; let i = path.length - 1;
// Track the state of characters (if any) we see before our first dot and // after any path separator we find let preDotState = 0;
// Get non-dir info for (; i >= start; --i) { const code = path.charCodeAt(i); if (isPosixPathSeparator(code)) { // If we reached a path separator that was not part of a set of path // separators at the end of the string, stop now if (!matchedSlash) { startPart = i + 1; break; } continue; } if (end === -1) { // We saw the first non-path separator, mark this as the end of our // extension matchedSlash = false; end = i + 1; } if (code === CHAR_DOT) { // If this is our first dot, mark it as the start of our extension if (startDot === -1) startDot = i; else if (preDotState !== 1) preDotState = 1; } else if (startDot !== -1) { // We saw a non-dot and non-path separator before our dot, so we should // have a good chance at having a non-empty extension preDotState = -1; } }
if ( startDot === -1 || end === -1 || // We saw a non-dot character immediately before the dot preDotState === 0 || // The (right-most) trimmed path component is exactly '..' (preDotState === 1 && startDot === end - 1 && startDot === startPart + 1) ) { if (end !== -1) { if (startPart === 0 && isAbsolute) { ret.base = ret.name = path.slice(1, end); } else { ret.base = ret.name = path.slice(startPart, end); } } // Fallback to '/' in case there is no basename ret.base = ret.base || "/"; } else { if (startPart === 0 && isAbsolute) { ret.name = path.slice(1, startDot); ret.base = path.slice(1, end); } else { ret.name = path.slice(startPart, startDot); ret.base = path.slice(startPart, end); } ret.ext = path.slice(startDot, end); }
if (startPart > 0) { ret.dir = stripTrailingSeparators( path.slice(0, startPart - 1), isPosixPathSeparator, ); } else if (isAbsolute) ret.dir = "/";
return ret;}