deno/core/normalize_path.rs

// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.

use std::path::Component;
use std::path::Path;
use std::path::PathBuf;

/// Normalize all intermediate components of the path (ie. remove "./" and "../" components).
/// Similar to `fs::canonicalize()` but doesn't resolve symlinks.
///
/// Taken from Cargo
/// https://github.com/rust-lang/cargo/blob/af307a38c20a753ec60f0ad18be5abed3db3c9ac/src/cargo/util/paths.rs#L60-L85
pub fn normalize_path<P: AsRef<Path>>(path: P) -> PathBuf {
  let mut components = path.as_ref().components().peekable();
  let mut ret =
    if let Some(c @ Component::Prefix(..)) = components.peek().cloned() {
      components.next();
      PathBuf::from(c.as_os_str())
    } else {
      PathBuf::new()
    };

  for component in components {
    match component {
      Component::Prefix(..) => unreachable!(),
      Component::RootDir => {
        ret.push(component.as_os_str());
      }
      Component::CurDir => {}
      Component::ParentDir => {
        ret.pop();
      }
      Component::Normal(c) => {
        ret.push(c);
      }
    }
  }
  ret
}