feat: update error notes for wfassoc

wfassoc/src/highlevel/program.rs

@@ -17,37 +17,36 @@ use thiserror::Error as TeError;
 /// Error occurs when trying converting [Schema] into [Program].
 #[derive(Debug, TeError)]
 pub enum ParseProgramError {
-    #[error("{0}")]
+    #[error("parsing into Program error: {0}")]
     BadExtBody(#[from] concept::BadExtBodyError),
-    #[error("{0}")]
+    #[error("parsing into Program error: {0}")]
     BadProgIdPart(#[from] concept::BadProgIdPartError),
-    #[error("{0}")]
+    #[error("parsing into Program error: {0}")]
     BadFileName(#[from] concept::BadFileNameError),
-    #[error("{0}")]
+    #[error("parsing into Program error: {0}")]
     ParseCmdLine(#[from] concept::ParseCmdLineError),
-    #[error("{0}")]
+    #[error("parsing into Program error: {0}")]
     CastOsStr(#[from] utilities::CastOsStrError),
-    #[error("given path doesn't has legal file name part")]
+
+    #[error("given path doesn't has legal file name part when parsing into Program")]
     NoFileNamePart,
-    #[error("given path doesn't has legal directory part")]
+    #[error("given path doesn't has legal directory part when parsing into Program")]
     NoDirNamePart,
-    #[error("given identifier is not presented in dict")]
-    NoSuchIdentifier,
-    #[error("extension name should not be empty")]
-    EmptyExtension,
-    #[error("given program identifier is not allowed")]
+    #[error("identifier {0} is unexpected not presented in HashMap when parsing into Program")]
+    NoSuchIdentifier(String),
+    #[error("bad program identifier found when parsing into Program")]
     BadIdentifier,
 }
 
 /// Error occurs when operating with [Program].
 #[derive(Debug, TeError)]
 pub enum ProgramError {
-    #[error("{0}")]
+    #[error("Program operation error: {0}")]
     Lowlevel(#[from] lowlevel::Error),
-    #[error("{0}")]
+    #[error("Program operation error: {0}")]
     LoadIconRc(#[from] concept::LoadIconRcError),
-    #[error("given index is invalid")]
-    BadIndex,
+    #[error("given file extension index {0} is invalid when visiting Program")]
+    BadIndex(usize),
 }
 
 // endregion
@@ -129,7 +128,7 @@ impl Program {
                 .get(*index)
                 .expect("unexpected invalid index")
                 .clone()),
-            None => Err(ParseProgramError::NoSuchIdentifier),
+            None => Err(ParseProgramError::NoSuchIdentifier(key.to_string())),
         }
     }
 
@@ -322,7 +321,10 @@ impl Program {
 
     pub fn resolve_ext(&self, index: usize) -> Result<ProgramSelfExtStatus, ProgramError> {
         // Fetch data
-        let progid_ext_key = self.ext_keys.get(index).ok_or(ProgramError::BadIndex)?;
+        let progid_ext_key = self
+            .ext_keys
+            .get(index)
+            .ok_or(ProgramError::BadIndex(index))?;
 
         // Try resolving name with string resource first,
         // and fallback to ProgId verbatim.
@@ -507,7 +509,7 @@ impl Program {
                 ext_key.ensure(scope)?;
                 ext_key.set_default(scope, Some(progid_key.inner()))?;
             }
-            None => return Err(ProgramError::BadIndex),
+            None => return Err(ProgramError::BadIndex(index)),
         };
 
         // Everything is okey.
@@ -529,7 +531,7 @@ impl Program {
                 ext_key.ensure(scope)?;
                 ext_key.set_default(scope, None)?;
             }
-            None => return Err(ProgramError::BadIndex),
+            None => return Err(ProgramError::BadIndex(index)),
         }
 
         // Everything is okey.
@@ -597,7 +599,7 @@ impl Program {
                 // Okey, return it.
                 Ok(Some(ProgramExtStatus::new(name, icon)))
             }
-            None => Err(ProgramError::BadIndex),
+            None => Err(ProgramError::BadIndex(index)),
         }
     }
 }

wfassoc/src/highlevel/schema.rs

@@ -7,7 +7,7 @@ use super::{Program, ParseProgramError};
 /// Error occurs when operating with [Schema].
 #[derive(Debug, TeError)]
 pub enum SchemaError {
-    #[error("duplicate key: {0}")]
+    #[error("duplicate key in Schema operation: {0}")]
     DuplicateKey(String),
 }
 

wfassoc/src/lowlevel.rs

@@ -10,27 +10,27 @@ use winreg::enums::{KEY_READ, KEY_WRITE};
 /// Error occurs in this module.
 #[derive(Debug, TeError)]
 pub enum Error {
-    #[error("can not perform this operation because lack essential privilege")]
+    #[error("some lowlevel operations require escalating privilege")]
     NoPrivilege,
-    #[error("given registry key is inexistant")]
+    #[error("given lowlevel registry key is not presented")]
     InexistantKey,
 
-    #[error("registry operation error: {0}")]
+    #[error("lowlevel registry operation error: {0}")]
     BadRegOp(#[from] std::io::Error),
-    #[error("{0}")]
+    #[error("unexpected blank registry key in lowlevel registry operation")]
     UnexpectedBlankKey(#[from] regext::BlankPathError),
 
-    #[error("{0}")]
+    #[error("lowlevel operation error: {0}")]
     ExpandEnvVar(#[from] concept::ExpandEnvVarError),
-    #[error("{0}")]
+    #[error("lowlevel operation error: {0}")]
     LoadIconRc(#[from] concept::LoadIconRcError),
-    #[error("{0}")]
+    #[error("lowlevel operation error: {0}")]
     LoadStrRc(#[from] concept::LoadStrRcError),
-    #[error("{0}")]
+    #[error("lowlevel operation error: {0}")]
     ParseVerb(#[from] concept::ParseVerbError),
-    #[error("{0}")]
+    #[error("lowlevel operation error: {0}")]
     ParseCmdLine(#[from] concept::ParseCmdLineError),
-    #[error("{0}")]
+    #[error("lowlevel operation error: {0}")]
     ParseExt(#[from] concept::ParseExtError),
 }
 

wfassoc/src/utilities.rs

@@ -9,7 +9,7 @@ use thiserror::Error as TeError;
 
 /// The error occurs when casting `OsStr` into `str`.
 #[derive(Debug, TeError)]
-#[error("fail to cast OS string into string")]
+#[error("fail to cast OS string into Rust string")]
 pub struct CastOsStrError {}
 
 impl CastOsStrError {

wfassoc/src/win32/concept.rs

@@ -42,6 +42,8 @@ impl Ext {
     /// Create an new file extension.
     ///
     /// `body` is the body of file extension (excluding dot, such as `jpg`).
+    /// Empty body is not allowed.
+    /// 
     /// If you want to create this struct with ordinary extension string like `.jpg`,
     /// please use `Ext::from_str()` or `parse::<Ext>()` instead.
     pub fn new(body: &str) -> Result<Self, BadExtBodyError> {
@@ -56,11 +58,17 @@ impl Ext {
     }
 
     /// Get the body part of file extension (excluding dot)
+    /// 
+    /// This struct promise that there is no possibility that return value is blank
+    /// (i.e. the body of file extension is empty).
     pub fn inner(&self) -> &str {
         &self.body
     }
 
     /// Get the body part of file extension (with leading dot)
+    /// 
+    /// This struct promise that there is no possibility that return value is dot only
+    /// (i.e. the body of file extension is empty).
     pub fn dotted_inner(&self) -> String {
         // Reuse Display trait result
         self.to_string()