Allow shell expanded strings in mod and import paths (#2059)

src/parser.rs

@@ -339,6 +339,7 @@ impl<'run, 'src> Parser<'run, 'src> {
           }
           Some(Keyword::Import)
             if self.next_are(&[Identifier, StringToken])
+              || self.next_are(&[Identifier, Identifier, StringToken])
               || self.next_are(&[Identifier, QuestionMark]) =>
           {
             self.presume_keyword(Keyword::Import)?;
@@ -353,6 +354,7 @@ impl<'run, 'src> Parser<'run, 'src> {
           }
           Some(Keyword::Mod)
             if self.next_are(&[Identifier, Identifier, StringToken])
+              || self.next_are(&[Identifier, Identifier, Identifier, StringToken])
               || self.next_are(&[Identifier, Identifier, Eof])
               || self.next_are(&[Identifier, Identifier, Eol])
               || self.next_are(&[Identifier, QuestionMark]) =>
@@ -363,7 +365,8 @@ impl<'run, 'src> Parser<'run, 'src> {
 
             let name = self.parse_name()?;
 
-            let relative = if self.next_is(StringToken) {
+            let relative = if self.next_is(StringToken) || self.next_are(&[Identifier, StringToken])
+            {
               Some(self.parse_string_literal()?)
             } else {
               None

tests/shell_expansion.rs

@@ -65,3 +65,35 @@ fn shell_expanded_strings_can_be_used_in_settings() {
     .stdout("dotenv-value\n")
     .run();
 }
+
+#[test]
+fn shell_expanded_strings_can_be_used_in_import_paths() {
+  Test::new()
+    .justfile(
+      "
+        import x'$JUST_TEST_VARIABLE'
+
+        foo: bar
+      ",
+    )
+    .write("import.just", "@bar:\n echo BAR")
+    .env("JUST_TEST_VARIABLE", "import.just")
+    .stdout("BAR\n")
+    .run();
+}
+
+#[test]
+fn shell_expanded_strings_can_be_used_in_mod_paths() {
+  Test::new()
+    .justfile(
+      "
+        mod foo x'$JUST_TEST_VARIABLE'
+      ",
+    )
+    .write("mod.just", "@bar:\n echo BAR")
+    .env("JUST_TEST_VARIABLE", "mod.just")
+    .args(["--unstable", "foo", "bar"])
+    .stdout("BAR\n")
+    .test_round_trip(false)
+    .run();
+}