der: add workspace-level clippy config (#2231)

Applies the workspace-level lints we've configured in other repos to
this repo, and enables them for the `der` crate, then fixes the lint
failures, either automatically or by adding the appropriate
documentation.

Author: tarcieri

.clippy.toml

@@ -0,0 +1,2 @@
+allow-unwrap-in-consts = true
+allow-unwrap-in-tests = true

Cargo.toml

@@ -60,3 +60,43 @@ tls_codec_derive = { path = "./tls_codec/derive" }
 x509-tsp = { path = "./x509-tsp" }
 x509-cert = { path = "./x509-cert" }
 x509-ocsp = { path = "./x509-ocsp" }
+
+[workspace.lints.clippy]
+borrow_as_ptr = "warn"
+cast_lossless = "warn"
+cast_possible_truncation = "warn"
+cast_possible_wrap = "warn"
+cast_precision_loss = "warn"
+cast_sign_loss = "warn"
+checked_conversions = "warn"
+doc_markdown = "warn"
+from_iter_instead_of_collect = "warn"
+implicit_saturating_sub = "warn"
+manual_assert = "warn"
+map_unwrap_or = "warn"
+missing_errors_doc = "warn"
+missing_panics_doc = "warn"
+mod_module_files = "warn"
+must_use_candidate = "warn"
+needless_range_loop = "allow"
+ptr_as_ptr = "warn"
+redundant_closure_for_method_calls = "warn"
+ref_as_ptr = "warn"
+return_self_not_must_use = "warn"
+semicolon_if_nothing_returned = "warn"
+trivially_copy_pass_by_ref = "warn"
+std_instead_of_alloc = "warn"
+std_instead_of_core = "warn"
+undocumented_unsafe_blocks = "warn"
+unnecessary_safety_comment = "warn"
+unwrap_in_result = "warn"
+unwrap_used = "warn"
+
+[workspace.lints.rust]
+missing_copy_implementations = "warn"
+missing_debug_implementations = "warn"
+missing_docs = "warn"
+trivial_casts = "warn"
+trivial_numeric_casts = "warn"
+unused_lifetimes = "warn"
+unused_qualifications = "warn"

der/Cargo.toml

@@ -44,6 +44,9 @@ oid = ["dep:const-oid"]
 pem = ["dep:pem-rfc7468", "alloc", "zeroize"]
 real = []
 
+[lints]
+workspace = true
+
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]

der/src/asn1/any.rs

@@ -37,6 +37,9 @@ impl<'a> AnyRef<'a> {
     };
 
     /// Create a new [`AnyRef`] from the provided [`Tag`] and DER bytes.
+    ///
+    /// # Errors
+    /// Returns [`Error`] with [`ErrorKind::Length`] if `bytes` is too long.
     pub const fn new(tag: Tag, bytes: &'a [u8]) -> Result<Self, Error> {
         match BytesRef::new(bytes) {
             Ok(value) => Ok(Self { tag, value }),
@@ -50,16 +53,21 @@ impl<'a> AnyRef<'a> {
     }
 
     /// Get the raw value for this [`AnyRef`] type as a byte slice.
+    #[must_use]
     pub fn value(self) -> &'a [u8] {
         self.value.as_slice()
     }
 
     /// Returns [`Tag`] and [`Length`] of self.
+    #[must_use]
     pub fn header(&self) -> Header {
         Header::new(self.tag, self.value.len())
     }
 
     /// Attempt to decode this [`AnyRef`] type into the inner value.
+    ///
+    /// # Errors
+    /// Returns `T::Error` if a decoding error occurred.
     pub fn decode_as<T>(self) -> Result<T, <T as DecodeValue<'a>>::Error>
     where
         T: Choice<'a> + DecodeValue<'a>,
@@ -68,6 +76,9 @@ impl<'a> AnyRef<'a> {
     }
 
     /// Attempt to decode this [`AnyRef`] type into the inner value.
+    ///
+    /// # Errors
+    /// Returns `T::Error` if a decoding error occurred.
     pub fn decode_as_encoding<T>(
         self,
         encoding: EncodingRules,
@@ -86,12 +97,16 @@ impl<'a> AnyRef<'a> {
     }
 
     /// Is this value an ASN.1 `NULL` value?
+    #[must_use]
     pub fn is_null(self) -> bool {
         self == Self::NULL
     }
 
     /// Attempt to decode this value an ASN.1 `SEQUENCE`, creating a new
     /// nested reader and calling the provided argument with it.
+    ///
+    /// # Errors
+    /// Returns `E` in the event an error is returned from `F` or if a decoding error occurs.
     pub fn sequence<F, T, E>(self, f: F) -> Result<T, E>
     where
         F: FnOnce(&mut SliceReader<'a>) -> Result<T, E>,
@@ -192,22 +207,30 @@ mod allocating {
 
     impl Any {
         /// Create a new [`Any`] from the provided [`Tag`] and DER bytes.
+        ///
+        /// # Errors
+        /// If `bytes` is too long.
         pub fn new(tag: Tag, bytes: impl Into<Box<[u8]>>) -> Result<Self, Error> {
             let value = BytesOwned::new(bytes)?;
             Ok(Self { tag, value })
         }
 
         /// Allow access to value
+        #[must_use]
         pub fn value(&self) -> &[u8] {
             self.value.as_slice()
         }
 
         /// Returns [`Tag`] and [`Length`] of self.
+        #[must_use]
         pub fn header(&self) -> Header {
             Header::new(self.tag, self.value.len())
         }
 
         /// Attempt to decode this [`Any`] type into the inner value.
+        ///
+        /// # Errors
+        /// Returns `T::Error` if a decoding error occurred.
         pub fn decode_as<'a, T>(&'a self) -> Result<T, <T as DecodeValue<'a>>::Error>
         where
             T: Choice<'a> + DecodeValue<'a>,
@@ -216,6 +239,9 @@ mod allocating {
         }
 
         /// Attempt to decode this [`Any`] type into the inner value with the given encoding rules.
+        ///
+        /// # Errors
+        /// Returns `T::Error` if a decoding error occurred.
         pub fn decode_as_encoding<'a, T>(
             &'a self,
             encoding: EncodingRules,
@@ -227,6 +253,9 @@ mod allocating {
         }
 
         /// Encode the provided type as an [`Any`] value.
+        ///
+        /// # Errors
+        /// If an encoding error occurred.
         pub fn encode_from<T>(msg: &T) -> Result<Self, Error>
         where
             T: Tagged + EncodeValue,
@@ -239,6 +268,9 @@ mod allocating {
 
         /// Attempt to decode this value an ASN.1 `SEQUENCE`, creating a new
         /// nested reader and calling the provided argument with it.
+        ///
+        /// # Errors
+        /// If a decoding error occurred.
         pub fn sequence<'a, F, T, E>(&'a self, f: F) -> Result<T, E>
         where
             F: FnOnce(&mut SliceReader<'a>) -> Result<T, E>,
@@ -248,6 +280,7 @@ mod allocating {
         }
 
         /// [`Any`] representation of the ASN.1 `NULL` type.
+        #[must_use]
         pub fn null() -> Self {
             Self {
                 tag: Tag::Null,
@@ -256,6 +289,7 @@ mod allocating {
         }
 
         /// Create a new [`AnyRef`] from the provided [`Any`] owned tag and bytes.
+        #[must_use]
         pub fn to_ref(&self) -> AnyRef<'_> {
             AnyRef {
                 tag: self.tag,
@@ -350,6 +384,7 @@ mod allocating {
 
     impl Any {
         /// Is this value an ASN.1 `NULL` value?
+        #[must_use]
         pub fn is_null(&self) -> bool {
             self.owned_to_ref() == AnyRef::NULL
         }