feat: add resolve_url_or_path (#7)

Cargo.toml

@@ -13,7 +13,7 @@ repository = "https://github.com/denoland/deno_path_util"
 percent-encoding = "2.3.0"
 thiserror = "2"
 sys_traits.workspace = true
-deno_error = "0.5.2"
+deno_error = { version = "0.5.2", features = ["url"] }
 url = "2.5.1"
 
 [dev-dependencies]
@@ -25,4 +25,4 @@ tempfile = "3.4.0"
 members = ["."]
 
 [workspace.dependencies]
-sys_traits = "0.1.0"
+sys_traits = "0.1.7"

src/fs.rs

@@ -107,7 +107,7 @@ pub fn atomic_write_file<
     data: &[u8],
     mode: u32,
   ) -> std::io::Result<()> {
-    let mut options = OpenOptions::write();
+    let mut options = OpenOptions::new_write();
     options.mode = Some(mode);
     let mut file = sys.fs_open(temp_file_path, &options)?;
     file.write_all(data)?;

src/lib.rs

@@ -5,6 +5,7 @@
 #![deny(clippy::unused_async)]
 #![deny(clippy::unnecessary_wraps)]
 
+use deno_error::JsError;
 use std::path::Component;
 use std::path::Path;
 use std::path::PathBuf;
@@ -174,7 +175,7 @@ pub fn normalize_path<P: AsRef<Path>>(path: P) -> PathBuf {
   inner(path.as_ref())
 }
 
-#[derive(Debug, Error, deno_error::JsError)]
+#[derive(Debug, Clone, Error, deno_error::JsError)]
 #[class(uri)]
 #[error("Could not convert path to URL.\n  Path: {0}")]
 pub struct PathToUrlError(pub PathBuf);
@@ -312,6 +313,75 @@ pub fn strip_unc_prefix(path: PathBuf) -> PathBuf {
   }
 }
 
+/// Returns true if the input string starts with a sequence of characters
+/// that could be a valid URI scheme, like 'https:', 'git+ssh:' or 'data:'.
+///
+/// According to RFC 3986 (https://tools.ietf.org/html/rfc3986#section-3.1),
+/// a valid scheme has the following format:
+///   scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
+///
+/// We additionally require the scheme to be at least 2 characters long,
+/// because otherwise a windows path like c:/foo would be treated as a URL,
+/// while no schemes with a one-letter name actually exist.
+pub fn specifier_has_uri_scheme(specifier: &str) -> bool {
+  let mut chars = specifier.chars();
+  let mut len = 0usize;
+  // The first character must be a letter.
+  match chars.next() {
+    Some(c) if c.is_ascii_alphabetic() => len += 1,
+    _ => return false,
+  }
+  // Second and following characters must be either a letter, number,
+  // plus sign, minus sign, or dot.
+  loop {
+    match chars.next() {
+      Some(c) if c.is_ascii_alphanumeric() || "+-.".contains(c) => len += 1,
+      Some(':') if len >= 2 => return true,
+      _ => return false,
+    }
+  }
+}
+
+#[derive(Debug, Clone, Error, JsError)]
+pub enum ResolveUrlOrPathError {
+  #[error(transparent)]
+  #[class(inherit)]
+  UrlParse(url::ParseError),
+  #[error(transparent)]
+  #[class(inherit)]
+  PathToUrl(PathToUrlError),
+}
+
+/// Takes a string representing either an absolute URL or a file path,
+/// as it may be passed to deno as a command line argument.
+/// The string is interpreted as a URL if it starts with a valid URI scheme,
+/// e.g. 'http:' or 'file:' or 'git+ssh:'. If not, it's interpreted as a
+/// file path; if it is a relative path it's resolved relative to passed
+/// `current_dir`.
+pub fn resolve_url_or_path(
+  specifier: &str,
+  current_dir: &Path,
+) -> Result<Url, ResolveUrlOrPathError> {
+  if specifier_has_uri_scheme(specifier) {
+    Url::parse(specifier).map_err(ResolveUrlOrPathError::UrlParse)
+  } else {
+    resolve_path(specifier, current_dir)
+      .map_err(ResolveUrlOrPathError::PathToUrl)
+  }
+}
+
+/// Converts a string representing a relative or absolute path into a
+/// ModuleSpecifier. A relative path is considered relative to the passed
+/// `current_dir`.
+pub fn resolve_path(
+  path_str: &str,
+  current_dir: &Path,
+) -> Result<Url, PathToUrlError> {
+  let path = current_dir.join(path_str);
+  let path = normalize_path(path);
+  url_from_file_path(&path)
+}
+
 pub fn get_atomic_path(sys: &impl SystemRandom, path: &Path) -> PathBuf {
   let rand = gen_rand_path_component(sys);
   let extension = format!("{rand}.tmp");
@@ -514,4 +584,141 @@ mod tests {
     assert_eq!(atomic_path.parent().unwrap(), path.parent().unwrap());
     assert_eq!(atomic_path.file_name().unwrap(), "c.3d3d3d3d.tmp");
   }
+
+  #[test]
+  fn test_specifier_has_uri_scheme() {
+    let tests = vec![
+      ("http://foo.bar/etc", true),
+      ("HTTP://foo.bar/etc", true),
+      ("http:ftp:", true),
+      ("http:", true),
+      ("hTtP:", true),
+      ("ftp:", true),
+      ("mailto:[email protected]", true),
+      ("git+ssh://[email protected]/denoland/deno", true),
+      ("blob:https://whatwg.org/mumbojumbo", true),
+      ("abc.123+DEF-ghi:", true),
+      ("abc.123+def-ghi:@", true),
+      ("", false),
+      (":not", false),
+      ("http", false),
+      ("c:dir", false),
+      ("X:", false),
+      ("./http://not", false),
+      ("1abc://kinda/but/no", false),
+      ("schluẞ://no/more", false),
+    ];
+
+    for (specifier, expected) in tests {
+      let result = specifier_has_uri_scheme(specifier);
+      assert_eq!(result, expected);
+    }
+  }
+
+  #[test]
+  fn test_resolve_url_or_path() {
+    // Absolute URL.
+    let mut tests: Vec<(&str, String)> = vec![
+      (
+        "http://deno.land/core/tests/006_url_imports.ts",
+        "http://deno.land/core/tests/006_url_imports.ts".to_string(),
+      ),
+      (
+        "https://deno.land/core/tests/006_url_imports.ts",
+        "https://deno.land/core/tests/006_url_imports.ts".to_string(),
+      ),
+    ];
+
+    // The local path tests assume that the cwd is the deno repo root. Note
+    // that we can't use `cwd` in miri tests, so we just use `/miri` instead.
+    let cwd = if cfg!(miri) {
+      PathBuf::from("/miri")
+    } else {
+      std::env::current_dir().unwrap()
+    };
+    let cwd_str = cwd.to_str().unwrap();
+
+    if cfg!(target_os = "windows") {
+      // Absolute local path.
+      let expected_url = "file:///C:/deno/tests/006_url_imports.ts";
+      tests.extend(vec![
+        (
+          r"C:/deno/tests/006_url_imports.ts",
+          expected_url.to_string(),
+        ),
+        (
+          r"C:\deno\tests\006_url_imports.ts",
+          expected_url.to_string(),
+        ),
+        (
+          r"\\?\C:\deno\tests\006_url_imports.ts",
+          expected_url.to_string(),
+        ),
+        // Not supported: `Url::from_file_path()` fails.
+        // (r"\\.\C:\deno\tests\006_url_imports.ts", expected_url.to_string()),
+        // Not supported: `Url::from_file_path()` performs the wrong conversion.
+        // (r"//./C:/deno/tests/006_url_imports.ts", expected_url.to_string()),
+      ]);
+
+      // Rooted local path without drive letter.
+      let expected_url = format!(
+        "file:///{}:/deno/tests/006_url_imports.ts",
+        cwd_str.get(..1).unwrap(),
+      );
+      tests.extend(vec![
+        (r"/deno/tests/006_url_imports.ts", expected_url.to_string()),
+        (r"\deno\tests\006_url_imports.ts", expected_url.to_string()),
+        (
+          r"\deno\..\deno\tests\006_url_imports.ts",
+          expected_url.to_string(),
+        ),
+        (r"\deno\.\tests\006_url_imports.ts", expected_url),
+      ]);
+
+      // Relative local path.
+      let expected_url = format!(
+        "file:///{}/tests/006_url_imports.ts",
+        cwd_str.replace('\\', "/")
+      );
+      tests.extend(vec![
+        (r"tests/006_url_imports.ts", expected_url.to_string()),
+        (r"tests\006_url_imports.ts", expected_url.to_string()),
+        (r"./tests/006_url_imports.ts", (*expected_url).to_string()),
+        (r".\tests\006_url_imports.ts", (*expected_url).to_string()),
+      ]);
+
+      // UNC network path.
+      let expected_url = "file://server/share/deno/cool";
+      tests.extend(vec![
+        (r"\\server\share\deno\cool", expected_url.to_string()),
+        (r"\\server/share/deno/cool", expected_url.to_string()),
+        // Not supported: `Url::from_file_path()` performs the wrong conversion.
+        // (r"//server/share/deno/cool", expected_url.to_string()),
+      ]);
+    } else {
+      // Absolute local path.
+      let expected_url = "file:///deno/tests/006_url_imports.ts";
+      tests.extend(vec![
+        ("/deno/tests/006_url_imports.ts", expected_url.to_string()),
+        ("//deno/tests/006_url_imports.ts", expected_url.to_string()),
+      ]);
+
+      // Relative local path.
+      let expected_url = format!("file://{cwd_str}/tests/006_url_imports.ts");
+      tests.extend(vec![
+        ("tests/006_url_imports.ts", expected_url.to_string()),
+        ("./tests/006_url_imports.ts", expected_url.to_string()),
+        (
+          "tests/../tests/006_url_imports.ts",
+          expected_url.to_string(),
+        ),
+        ("tests/./006_url_imports.ts", expected_url),
+      ]);
+    }
+
+    for (specifier, expected_url) in tests {
+      let url = resolve_url_or_path(specifier, &cwd).unwrap().to_string();
+      assert_eq!(url, expected_url);
+    }
+  }
 }