yahoo-finance2
Version:
JS API for Yahoo Finance
97 lines (96 loc) • 3.77 kB
JavaScript
;
// Copyright 2018-2025 the Deno authors. MIT license.
// This module is browser compatible.
Object.defineProperty(exports, "__esModule", { value: true });
exports.extname = extname;
const constants_js_1 = require("../_common/constants.js");
const assert_path_js_1 = require("../_common/assert_path.js");
const _util_js_1 = require("./_util.js");
const from_file_url_js_1 = require("./from_file_url.js");
/**
* Return the extension of the `path` with leading period.
*
* @example Usage
* ```ts
* import { extname } from "@std/path/posix/extname";
* import { assertEquals } from "@std/assert";
*
* assertEquals(extname("/home/user/Documents/file.ts"), ".ts");
* assertEquals(extname("/home/user/Documents/"), "");
* assertEquals(extname("/home/user/Documents/image.png"), ".png");
* assertEquals(extname(new URL("file:///home/user/Documents/file.ts")), ".ts");
* assertEquals(extname(new URL("file:///home/user/Documents/file.ts?a=b")), ".ts");
* assertEquals(extname(new URL("file:///home/user/Documents/file.ts#header")), ".ts");
* ```
*
* @example Working with URLs
*
* Note: This function doesn't automatically strip hash and query parts from
* URLs. If your URL contains a hash or query, remove them before passing the
* URL to the function. This can be done by passing the URL to `new URL(url)`,
* and setting the `hash` and `search` properties to empty strings.
*
* ```ts
* import { extname } from "@std/path/posix/extname";
* import { assertEquals } from "@std/assert";
*
* assertEquals(extname("https://deno.land/std/path/mod.ts"), ".ts");
* assertEquals(extname("https://deno.land/std/path/mod.ts?a=b"), ".ts?a=b");
* assertEquals(extname("https://deno.land/std/path/mod.ts#header"), ".ts#header");
* ```
*
* @param path The path to get the extension from.
* @returns The extension (ex. for `file.ts` returns `.ts`).
*/
function extname(path) {
if (path instanceof URL) {
path = (0, from_file_url_js_1.fromFileUrl)(path);
}
(0, assert_path_js_1.assertPath)(path);
let startDot = -1;
let startPart = 0;
let end = -1;
let matchedSlash = true;
// Track the state of characters (if any) we see before our first dot and
// after any path separator we find
let preDotState = 0;
for (let i = path.length - 1; i >= 0; --i) {
const code = path.charCodeAt(i);
if ((0, _util_js_1.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 === constants_js_1.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)) {
return "";
}
return path.slice(startDot, end);
}