Reject dot-containing package name (#320)

CHANGELOG.md

@@ -7,6 +7,8 @@
 
 * savvy now generates a reduced number of R functions.
 
+* savvy-cli now rejects a package name containing `.`.
+
 ## [v0.7.1] (2024-10-21)
 
 ### Bug fixes

savvy-cli/src/main.rs

@@ -108,10 +108,26 @@ fn parse_description(path: &Path) -> PackageDescription {
     }
 
     if package_name_orig.is_empty() {
-        eprintln!("{} is not an R package root", path.to_string_lossy());
+        eprintln!(
+            "
+{} is not an R package root.
+",
+            path.to_string_lossy()
+        );
         std::process::exit(4);
     }
 
+    if package_name_orig.contains('.') {
+        let package_name_new = dot_containing_to_camel_case(package_name_orig);
+        eprintln!(
+            r#"
+savvy doesn't support a package name with "." ({package_name_orig}).
+Please consider renaming it to "{package_name_new}".
+"#,
+        );
+        std::process::exit(5);
+    }
+
     PackageDescription {
         package_name: package_name_orig.to_string(),
         has_sysreq,

savvy-cli/src/utils.rs

@@ -17,6 +17,29 @@ pub(crate) fn to_snake_case(x: &str) -> String {
     out
 }
 
+pub(crate) fn dot_containing_to_camel_case(x: &str) -> String {
+    x.split('.')
+        .enumerate()
+        .map(|(i_split, split)| {
+            if i_split == 0 {
+                return split.to_string();
+            }
+            split
+                .chars()
+                .enumerate()
+                .map(|(i_char, c)| {
+                    if i_char == 0 {
+                        c.to_uppercase().next().unwrap()
+                    } else {
+                        c.to_lowercase().next().unwrap()
+                    }
+                })
+                .collect()
+        })
+        .collect::<Vec<String>>()
+        .join("")
+}
+
 pub(crate) fn canonicalize(path: &Path) -> Result<String, std::io::Error> {
     let crate_dir_abs = path.canonicalize()?;
     let crate_dir_abs = crate_dir_abs.to_string_lossy();
@@ -42,4 +65,11 @@ mod tests {
         assert_eq!(&to_snake_case("FooBar"), "foo_bar");
         assert_eq!(&to_snake_case("fooBarBaz"), "foo_bar_baz");
     }
+
+    #[test]
+    fn test_camel_case() {
+        assert_eq!(&dot_containing_to_camel_case("foo.bar"), "fooBar");
+        assert_eq!(&dot_containing_to_camel_case("foo.bar.baz"), "fooBarBaz");
+        assert_eq!(&dot_containing_to_camel_case("foo.BAR.baz"), "fooBarBaz");
+    }
 }