Expand tilde in import and module paths (#1792)

Cargo.toml

@@ -24,6 +24,7 @@ camino = "1.0.4"
 clap = { version = "2.33.0", features = ["wrap_help"] }
 ctrlc = { version = "3.1.1", features = ["termination"] }
 derivative = "2.0.0"
+dirs = "5.0.1"
 dotenvy = "0.15"
 edit-distance = "2.0.0"
 env_logger = "0.10.0"

README.md

@@ -2358,7 +2358,8 @@ A
 ```
 
 The `import` path can be absolute or relative to the location of the justfile
-containing it.
+containing it. A leading `~/` in the import path is replaced with the current
+users home directory.
 
 Justfiles are insensitive to order, so included files can reference variables
 and recipes defined after the `import` statement.
@@ -2406,7 +2407,19 @@ If a module is named `foo`, just will search for the module file in `foo.just`,
 `foo/mod.just`, `foo/justfile`, and `foo/.justfile`. In the latter two cases,
 the module file may have any capitalization.
 
-Environment files are loaded for the root justfile.
+Module statements may be of the form:
+
+```mf
+mod foo 'PATH'
+```
+
+Which loads the module's source file from `PATH`, instead of from the usual
+locations. A leading `~/` in `PATH` is replaced with the current user's home
+directory.
+
+Environment files are only loaded for the root justfile, and loaded environment
+variables are available in submodules. Settings in submodules that affect
+enviroment file loading are ignored.
 
 Recipes in submodules without the `[no-cd]` attribute run with the working
 directory set to the directory containing the submodule source file.

src/compiler.rs

@@ -41,7 +41,7 @@ impl Compiler {
             let parent = current.parent().unwrap();
 
             let import = if let Some(path) = path {
-              parent.join(&path.cooked)
+              parent.join(Self::expand_tilde(&path.cooked)?)
             } else {
               Self::find_module_file(parent, *name)?
             };
@@ -53,7 +53,11 @@ impl Compiler {
             stack.push((import, depth + 1));
           }
           Item::Import { relative, absolute } => {
-            let import = current.parent().unwrap().join(&relative.cooked).lexiclean();
+            let import = current
+              .parent()
+              .unwrap()
+              .join(Self::expand_tilde(&relative.cooked)?)
+              .lexiclean();
             if srcs.contains_key(&import) {
               return Err(Error::CircularImport { current, import });
             }
@@ -117,6 +121,16 @@ impl Compiler {
     }
   }
 
+  fn expand_tilde(path: &str) -> RunResult<'static, PathBuf> {
+    Ok(if let Some(path) = path.strip_prefix("~/") {
+      dirs::home_dir()
+        .ok_or(Error::Homedir)?
+        .join(path.trim_start_matches('/'))
+    } else {
+      PathBuf::from(path)
+    })
+  }
+
   #[cfg(test)]
   pub(crate) fn test_compile(src: &str) -> CompileResult<Justfile> {
     let tokens = Lexer::test_lex(src)?;

src/error.rs

@@ -95,6 +95,7 @@ pub(crate) enum Error<'src> {
   GetConfirmation {
     io_error: io::Error,
   },
+  Homedir,
   InitExists {
     justfile: PathBuf,
   },
@@ -347,6 +348,9 @@ impl<'src> ColorDisplay for Error<'src> {
       GetConfirmation { io_error } => {
         write!(f, "Failed to read confirmation from stdin: {io_error}")?;
       }
+      Homedir => {
+        write!(f, "Failed to get homedir")?;
+      }
       InitExists { justfile } => {
         write!(f, "Justfile `{}` already exists", justfile.display())?;
       }

tests/imports.rs

@@ -152,3 +152,20 @@ fn recipes_in_import_are_overridden_by_recipes_in_parent() {
     .stdout("ROOT\n")
     .run();
 }
+
+#[cfg(not(windows))]
+#[test]
+fn import_paths_beginning_with_tilde_are_expanded_to_homdir() {
+  Test::new()
+    .write("foobar/mod.just", "foo:\n @echo FOOBAR")
+    .justfile(
+      "
+        import '~/mod.just'
+      ",
+    )
+    .test_round_trip(false)
+    .arg("foo")
+    .stdout("FOOBAR\n")
+    .env("HOME", "foobar")
+    .run();
+}

tests/modules.rs

@@ -529,3 +529,22 @@ fn submodule_shebang_recipes_run_in_submodule_directory() {
     .stdout("BAR")
     .run();
 }
+
+#[cfg(not(windows))]
+#[test]
+fn module_paths_beginning_with_tilde_are_expanded_to_homdir() {
+  Test::new()
+    .write("foobar/mod.just", "foo:\n @echo FOOBAR")
+    .justfile(
+      "
+        mod foo '~/mod.just'
+      ",
+    )
+    .test_round_trip(false)
+    .arg("--unstable")
+    .arg("foo")
+    .arg("foo")
+    .stdout("FOOBAR\n")
+    .env("HOME", "foobar")
+    .run();
+}