feat(path): single file exports

path/basename.ts

@@ -0,0 +1,62 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { isWindows } from "../_util/os.ts";
+import { CHAR_COLON } from "./_constants.ts";
+import {
+  assertPath,
+  isPathSeparator,
+  isPosixPathSeparator,
+  isWindowsDeviceRoot,
+  lastPathSegment,
+  stripSuffix,
+  stripTrailingSeparators,
+} from "./_util.ts";
+
+function posixBasename(path: string, suffix = ""): string {
+  const lastSegment = lastPathSegment(path, isPosixPathSeparator);
+  const strippedSegment = stripTrailingSeparators(
+    lastSegment,
+    isPosixPathSeparator,
+  );
+  return suffix ? stripSuffix(strippedSegment, suffix) : strippedSegment;
+}
+
+function windowsBasename(path: string, suffix = ""): string {
+  // Check for a drive letter prefix so as not to mistake the following
+  // path separator as an extra separator at the end of the path that can be
+  // disregarded
+  let start = 0;
+  if (path.length >= 2) {
+    const drive = path.charCodeAt(0);
+    if (isWindowsDeviceRoot(drive)) {
+      if (path.charCodeAt(1) === CHAR_COLON) start = 2;
+    }
+  }
+
+  const lastSegment = lastPathSegment(path, isPathSeparator, start);
+  const strippedSegment = stripTrailingSeparators(lastSegment, isPathSeparator);
+  return suffix ? stripSuffix(strippedSegment, suffix) : strippedSegment;
+}
+
+/**
+ * Return the last portion of a `path`.
+ * Trailing directory separators are ignored, and optional suffix is removed.
+ *
+ * @param path - path to extract the name from.
+ * @param [suffix] - suffix to remove from extracted name.
+ */
+export function basename(path: string, suffix = ""): string {
+  assertPath(path);
+  if (path.length === 0) return path;
+  if (typeof suffix !== "string") {
+    throw new TypeError(
+      `Suffix must be a string. Received ${JSON.stringify(suffix)}`,
+    );
+  }
+
+  if (isWindows) {
+    return windowsBasename(path, suffix);
+  }
+  return posixBasename(path, suffix);
+}

path/dirname.ts

@@ -0,0 +1,144 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { isWindows } from "../_util/os.ts";
+import { CHAR_COLON } from "./_constants.ts";
+import {
+  assertPath,
+  isPathSeparator,
+  isPosixPathSeparator,
+  isWindowsDeviceRoot,
+  stripTrailingSeparators,
+} from "./_util.ts";
+
+function posixDirname(path: string): string {
+  let end = -1;
+  let matchedNonSeparator = false;
+
+  for (let i = path.length - 1; i >= 1; --i) {
+    if (isPosixPathSeparator(path.charCodeAt(i))) {
+      if (matchedNonSeparator) {
+        end = i;
+        break;
+      }
+    } else {
+      matchedNonSeparator = true;
+    }
+  }
+
+  // No matches. Fallback based on provided path:
+  //
+  // - leading slashes paths
+  //     "/foo" => "/"
+  //     "///foo" => "/"
+  // - no slash path
+  //     "foo" => "."
+  if (end === -1) {
+    return isPosixPathSeparator(path.charCodeAt(0)) ? "/" : ".";
+  }
+
+  return stripTrailingSeparators(
+    path.slice(0, end),
+    isPosixPathSeparator,
+  );
+}
+
+function windowsDirname(path: string): string {
+  const len = path.length;
+  let rootEnd = -1;
+  let end = -1;
+  let matchedSlash = true;
+  let offset = 0;
+  const code = path.charCodeAt(0);
+
+  // Try to match a root
+  if (len > 1) {
+    if (isPathSeparator(code)) {
+      // Possible UNC root
+
+      rootEnd = offset = 1;
+
+      if (isPathSeparator(path.charCodeAt(1))) {
+        // Matched double path separator at beginning
+        let j = 2;
+        let last = j;
+        // Match 1 or more non-path separators
+        for (; j < len; ++j) {
+          if (isPathSeparator(path.charCodeAt(j))) break;
+        }
+        if (j < len && j !== last) {
+          // Matched!
+          last = j;
+          // Match 1 or more path separators
+          for (; j < len; ++j) {
+            if (!isPathSeparator(path.charCodeAt(j))) break;
+          }
+          if (j < len && j !== last) {
+            // Matched!
+            last = j;
+            // Match 1 or more non-path separators
+            for (; j < len; ++j) {
+              if (isPathSeparator(path.charCodeAt(j))) break;
+            }
+            if (j === len) {
+              // We matched a UNC root only
+              return path;
+            }
+            if (j !== last) {
+              // We matched a UNC root with leftovers
+
+              // Offset by 1 to include the separator after the UNC root to
+              // treat it as a "normal root" on top of a (UNC) root
+              rootEnd = offset = j + 1;
+            }
+          }
+        }
+      }
+    } else if (isWindowsDeviceRoot(code)) {
+      // Possible device root
+
+      if (path.charCodeAt(1) === CHAR_COLON) {
+        rootEnd = offset = 2;
+        if (len > 2) {
+          if (isPathSeparator(path.charCodeAt(2))) rootEnd = offset = 3;
+        }
+      }
+    }
+  } else if (isPathSeparator(code)) {
+    // `path` contains just a path separator, exit early to avoid
+    // unnecessary work
+    return path;
+  }
+
+  for (let i = len - 1; i >= offset; --i) {
+    if (isPathSeparator(path.charCodeAt(i))) {
+      if (!matchedSlash) {
+        end = i;
+        break;
+      }
+    } else {
+      // We saw the first non-path separator
+      matchedSlash = false;
+    }
+  }
+
+  if (end === -1) {
+    if (rootEnd === -1) return ".";
+    else end = rootEnd;
+  }
+  return stripTrailingSeparators(path.slice(0, end), isPosixPathSeparator);
+}
+
+/**
+ * Return the directory path of a `path`.
+ * @param path - path to extract the directory from.
+ */
+export function dirname(path: string): string {
+  assertPath(path);
+  if (path.length === 0) return ".";
+
+  if (isWindows) {
+    return windowsDirname(path);
+  }
+  return posixDirname(path);
+}

path/extname.ts

@@ -0,0 +1,139 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { isWindows } from "../_util/os.ts";
+import { CHAR_COLON, CHAR_DOT } from "./_constants.ts";
+import {
+  assertPath,
+  isPathSeparator,
+  isPosixPathSeparator,
+  isWindowsDeviceRoot,
+} from "./_util.ts";
+
+function posixExtname(path: string): string {
+  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 (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)
+  ) {
+    return "";
+  }
+  return path.slice(startDot, end);
+}
+
+function windowsExtname(path: string): string {
+  let start = 0;
+  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;
+
+  // Check for a drive letter prefix so as not to mistake the following
+  // path separator as an extra separator at the end of the path that can be
+  // disregarded
+
+  if (
+    path.length >= 2 &&
+    path.charCodeAt(1) === CHAR_COLON &&
+    isWindowsDeviceRoot(path.charCodeAt(0))
+  ) {
+    start = startPart = 2;
+  }
+
+  for (let i = path.length - 1; i >= start; --i) {
+    const code = path.charCodeAt(i);
+    if (isPathSeparator(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)
+  ) {
+    return "";
+  }
+  return path.slice(startDot, end);
+}
+
+/**
+ * @deprecated (will be removed after 1.0.0) Import from `std/path/extname.ts` instead.
+ *
+ * Return the extension of the `path` with leading period.
+ * @param path with extension
+ * @returns extension (ex. for `file.ts` returns `.ts`)
+ */
+export function extname(path: string): string {
+  assertPath(path);
+
+  if (isWindows) {
+    return windowsExtname(path);
+  }
+  return posixExtname(path);
+}

path/format.ts

@@ -0,0 +1,23 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { isWindows } from "../_util/os.ts";
+import { FormatInputPathObject } from "./_interface.ts";
+import { _format } from "./_util.ts";
+
+/**
+ * Generate a path from `FormatInputPathObject` object.
+ * @param pathObject with path
+ */
+export function format(pathObject: FormatInputPathObject): string {
+  if (pathObject === null || typeof pathObject !== "object") {
+    throw new TypeError(
+      `The "pathObject" argument must be of type Object. Received type ${typeof pathObject}`,
+    );
+  }
+
+  if (isWindows) {
+    return _format("\\", pathObject);
+  }
+  return _format("/", pathObject);
+}