feat: Add linting for add-newline attribute

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/error.rs b/src/error.rs
index 60c850e..0057f37 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -126,6 +126,20 @@ pub enum SubplotError {
     #[error("Duplicate embedded file name: {0}")]
     DuplicateEmbeddedFilename(String),
 
+    /// Embedded file has more than one `add-newline` attribute
+    ///
+    /// The `add-newline` attribute can only be specified once for any given
+    /// embedded file
+    #[error("Embedded file {0} has more than one `add-newline` attribute")]
+    RepeatedAddNewlineAttribute(String),
+
+    /// Unrecognised `add-newline` attribute value on an embedded file
+    ///
+    /// The `add-newline` attribute can only take the values `auto`, `yes`,
+    /// and `no`.
+    #[error("Embedded file {0} has unrecognised `add-newline={}` - valid values are auto/yes/no")]
+    UnrecognisedAddNewline(String, String),
+
     /// Couldn't determine base directory from input file name.
     ///
     /// Subplot needs to to determine the base directory for files