From 0f4cfacfbe9d77f4615aee7b8d067fc099f5a917 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Finn=20B=C3=B6ger?= <finnboeger@googlemail.com>
Date: Sun, 16 Aug 2020 16:01:51 +0200
Subject: [PATCH 1/2] pass along path when canonicalization fails

---
 src/loader.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/loader.rs b/src/loader.rs
index 9690711..0f1f985 100644
--- a/src/loader.rs
+++ b/src/loader.rs
@@ -23,8 +23,9 @@ error_chain! {
             display("decoding error: {}", msg)
         }
         #[doc="error in path canonicalization"]
-        CanonicalizationError {
+        CanonicalizationError(msg: String) {
             description("canonicalization error")
+            display("canonicalization error: {}", msg)
         }
         #[doc="error in parsing the song header"]
         HeaderParsingError {
@@ -72,7 +73,7 @@ fn canonicalize_path<B: AsRef<Path>>(
                 tmp_path.push(x);
                 let result = tmp_path
                     .canonicalize()
-                    .chain_err(|| ErrorKind::CanonicalizationError)?;
+                    .chain_err(|| ErrorKind::CanonicalizationError(format!("{:?}", tmp_path)))?;
                 Source::Local(result)
             }
         })

From 597792e0a810c9aa1d9fb4db71b3096f5930cc12 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Finn=20B=C3=B6ger?= <finnboeger@googlemail.com>
Date: Sun, 16 Aug 2020 19:08:27 +0200
Subject: [PATCH 2/2] pass along missing header fields and failed line

---
 src/loader.rs | 24 ++++++++++++++++++++----
 src/parser.rs | 12 +++++++++---
 2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/src/loader.rs b/src/loader.rs
index 0f1f985..8ff35ca 100644
--- a/src/loader.rs
+++ b/src/loader.rs
@@ -28,12 +28,14 @@ error_chain! {
             display("canonicalization error: {}", msg)
         }
         #[doc="error in parsing the song header"]
-        HeaderParsingError {
+        HeaderParsingError(msg: String) {
             description("header parsing error")
+            display("header parsing error: {}", msg)
         }
         #[doc="error in parsing the songs lines"]
-        LinesParsingError {
+        LinesParsingError(msg: String) {
             description("lines parsing error")
+            display("lines parsing error: {}", msg)
         }
     }
 }
@@ -92,8 +94,22 @@ pub fn parse_txt_song<P: AsRef<Path>>(path: P) -> Result<TXTSong> {
     let txt = read_file_to_string(path)?;
 
     let mut txt_song = TXTSong {
-        header: parse_txt_header_str(txt.as_ref()).chain_err(|| ErrorKind::HeaderParsingError)?,
-        lines: parse_txt_lines_str(txt.as_ref()).chain_err(|| ErrorKind::LinesParsingError)?,
+        header: parse_txt_header_str(txt.as_ref())
+            .map_err(|e| {
+                let s = e.to_string();
+                Error::with_chain(
+                    e,
+                    ErrorKind::HeaderParsingError(s),
+                )
+            })?,
+        lines: parse_txt_lines_str(txt.as_ref())
+            .map_err(|e| {
+                let s = e.to_string();
+                Error::with_chain(
+                    e,
+                    ErrorKind::LinesParsingError(s)
+                )
+            })?,
     };
 
     // canonicalize paths
diff --git a/src/parser.rs b/src/parser.rs
index 8fa10c8..0758868 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -10,8 +10,9 @@ error_chain! {
             display("additional {} tag found in line: {}", line, tag)
         }
         #[doc="an essential header is missing"]
-        MissingEssential {
+        MissingEssential(fields: Vec<String>) {
             description("essential header is missing")
+            display("essential header is missing. Missing headers: {:?}", fields)
         }
 
         #[doc="value could not be parsed"]
@@ -232,7 +233,7 @@ pub fn parse_txt_header_str(txt_str: &str) -> Result<Header> {
 
     // build header from Options
     if let (Some(title), Some(artist), Some(bpm), Some(audio_path)) =
-        (opt_title, opt_artist, opt_bpm, opt_audio_path)
+        (opt_title.clone(), opt_artist.clone(), opt_bpm.clone(), opt_audio_path.clone())
     {
         let header = Header {
             title,
@@ -255,8 +256,13 @@ pub fn parse_txt_header_str(txt_str: &str) -> Result<Header> {
         // header complete
         Ok(header)
     } else {
+        let mut fields = Vec::new();
+        if opt_title.is_none() { fields.push("Title".to_string()) }
+        if opt_artist.is_none() { fields.push("Artist".to_string()) }
+        if opt_bpm.is_none() { fields.push("BPM".to_string()) }
+        if opt_audio_path.is_none() { fields.push("Audio Path".to_string()) }
         // essential field is missing
-        bail!(ErrorKind::MissingEssential)
+        bail!(ErrorKind::MissingEssential(fields))
     }
 }