fix: report name of missing bindings or functions file in error msg

1 files changed, 4 insertions, 2 deletions

diff --git a/src/codegen.rs b/src/codegen.rs
index db31765..9895783 100644
--- a/src/codegen.rs
+++ b/src/codegen.rs
@@ -1,4 +1,4 @@
-use crate::{Document, TemplateSpec};
+use crate::{Document, SubplotError, TemplateSpec};
 use std::collections::HashMap;
 use std::fs::File;
 use std::io::prelude::{Read, Write};
@@ -44,7 +44,9 @@ fn context(doc: &mut Document) -> Result<Context> {
     let funcs_filenames = doc.meta().functions_filenames();
     let mut funcs = String::new();
     for filename in funcs_filenames {
-        funcs.push_str(&cat(filename)?);
+        let content =
+            cat(filename).map_err(|e| SubplotError::FunctionsFileNotFound(filename.into(), e))?;
+        funcs.push_str(&content);
     }
     context.insert("functions", &funcs);