error utils (reusable)

Cargo.lock

@@ -3876,6 +3876,13 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "error_utils"
+version = "0.0.1"
+dependencies = [
+ "regex",
+]
+
 [[package]]
 name = "errors"
 version = "0.0.1"
@@ -11234,6 +11241,7 @@ dependencies = [
  "elasticsearch",
  "elasticsearch_schema",
  "enums",
+ "error_utils",
  "errors",
  "fal_client",
  "ffmpeg_utils",

Cargo.toml

@@ -59,6 +59,7 @@ members = [
   "crates/lib/data/primitives",
   "crates/lib/data/web_base64",
   "crates/lib/easyenv", # NB: Vendored version of https://github.com/echelon/easyenv.rs that we'll improve.
+  "crates/lib/error_utils",
   "crates/lib/errors",
   "crates/lib/ffmpeg_utils",
   "crates/lib/files/file_to_base64_url",
@@ -236,6 +237,7 @@ cookie_store = { path = "crates/lib/cookie_store" }
 crockford = { path = "crates/lib/data/crockford" }
 easyenv = { path = "crates/lib/easyenv" }
 enums = { path = "crates/schema/public/enums" }
+error_utils = { path = "crates/lib/error_utils" }
 errors = { path = "crates/lib/errors" }
 fal_client = { path = "crates/api_clients/fal_client" }
 ffmpeg_utils = { path = "crates/lib/ffmpeg_utils" }

crates/lib/error_utils/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "error_utils"
+edition = "2021"
+version = "0.0.1"
+authors = [
+    "Brandon Thomas <bt@brand.io>",
+    "Brandon Thomas <echelon@gmail.com>",
+]
+publish = false
+
+[lib]
+name = "error_utils"
+path = "src/lib.rs"
+
+[dependencies]
+regex.workspace = true

crates/lib/error_utils/src/lib.rs

@@ -0,0 +1 @@
+pub mod try_error_name;

crates/lib/error_utils/src/try_error_name.rs

@@ -0,0 +1,157 @@
+use regex::Regex;
+use std::sync::LazyLock;
+
+/// Regex that matches CamelCase type names with an optional `::Variant` suffix.
+/// E.g. `CommonWebError::InvalidRequest`, `EnvError`, `KinoviError::RequestError`.
+static ERROR_NAME_RE: LazyLock<Regex> = LazyLock::new(|| {
+  Regex::new(r"[A-Z][0-9a-z]+(?:[A-Z][0-9a-z]+)*(?:::[A-Z][0-9a-z]+(?:[A-Z][0-9a-z]+)*)?")
+      .expect("error name regex should compile")
+});
+
+/// Try to extract a human-readable error title from the causal error's Debug
+/// representation. Looks for CamelCase type names like `EnvError::NotUnicode`.
+pub fn try_error_name(error: &dyn std::error::Error) -> Option<String> {
+  let debug_str = format!("{:?}", error);
+  try_extract_error_name(&debug_str)
+}
+
+/// Extract the leading CamelCase error name (with optional `::Variant`) from
+/// a Debug-formatted error string. Returns `None` if no match is found.
+///
+/// ```text
+/// "CommonWebError::InvalidRequest(\"bad\")" → Some("CommonWebError::InvalidRequest")
+/// "EnvError::ParseError { reason: \"foo\" }" → Some("EnvError::ParseError")
+/// "just a plain string"                      → None
+/// ```
+pub (crate) fn try_extract_error_name(debug_str: &str) -> Option<String> {
+  ERROR_NAME_RE.find(debug_str)
+      .map(|m| m.as_str().to_string())
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  // --- try_extract_error_name tests ---
+
+  #[test]
+  fn extract_just_error_name() {
+    assert_eq!(
+      try_extract_error_name("JustErrorName"),
+      Some("JustErrorName".to_string()),
+    );
+  }
+
+  #[test]
+  fn extract_error_with_variant_and_string_payload() {
+    assert_eq!(
+      try_extract_error_name(r#"CommonWebError::InvalidRequest("Invalid request")"#),
+      Some("CommonWebError::InvalidRequest".to_string()),
+    );
+  }
+
+  #[test]
+  fn extract_error_with_unit_variant() {
+    assert_eq!(
+      try_extract_error_name("EnvError::NotUnicode"),
+      Some("EnvError::NotUnicode".to_string()),
+    );
+  }
+
+  #[test]
+  fn extract_error_with_struct_payload() {
+    assert_eq!(
+      try_extract_error_name(r#"EnvError::ParseError { reason: "foo" }"#),
+      Some("EnvError::ParseError".to_string()),
+    );
+  }
+
+  #[test]
+  fn extract_error_with_tuple_payload() {
+    assert_eq!(
+      try_extract_error_name("KinoviError::RequestError(asdf)"),
+      Some("KinoviError::RequestError".to_string()),
+    );
+  }
+
+  #[test]
+  fn extract_error_with_nested_errors() {
+    assert_eq!(
+      try_extract_error_name(
+        "ComplexError::SomeError(SomeError::SomeVariant(SomeInnerError::SomeInnerVariant))"
+      ),
+      Some("ComplexError::SomeError".to_string()),
+    );
+  }
+
+  #[test]
+  fn extract_error_with_struct_containing_nested() {
+    assert_eq!(
+      try_extract_error_name(
+        "WrappedError::Variant { inner: SomeInnerError::SomeInnerVariant }"
+      ),
+      Some("WrappedError::Variant".to_string()),
+    );
+  }
+
+  #[test]
+  fn no_match_for_lowercase_string() {
+    assert_eq!(
+      try_extract_error_name("just a plain error message with no type name"),
+      None,
+    );
+  }
+
+  #[test]
+  fn no_match_for_empty_string() {
+    assert_eq!(try_extract_error_name(""), None);
+  }
+
+  #[test]
+  fn single_word_camel_case() {
+    assert_eq!(
+      try_extract_error_name("Error"),
+      Some("Error".to_string()),
+    );
+  }
+
+  // --- try_error_title tests (with real error types) ---
+
+  #[test]
+  fn title_from_io_error() {
+    let err: Box<dyn std::error::Error> = Box::new(
+      std::io::Error::new(std::io::ErrorKind::NotFound, "file not found"),
+    );
+    let title = try_error_name(err.as_ref());
+    assert!(title.is_some());
+  }
+
+  /// A simple custom error for testing.
+  #[derive(Debug)]
+  enum TestAppError {
+    DatabaseTimeout,
+    InvalidInput(String),
+  }
+
+  impl std::fmt::Display for TestAppError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+      write!(f, "{:?}", self)
+    }
+  }
+
+  impl std::error::Error for TestAppError {}
+
+  #[test]
+  fn title_from_custom_unit_variant() {
+    let err = TestAppError::DatabaseTimeout;
+    let title = try_error_name(&err);
+    assert_eq!(title, Some("DatabaseTimeout".to_string()));
+  }
+
+  #[test]
+  fn title_from_custom_tuple_variant() {
+    let err = TestAppError::InvalidInput("bad data".to_string());
+    let title = try_error_name(&err);
+    assert_eq!(title, Some("InvalidInput".to_string()));
+  }
+}

crates/service/web/storyteller_web/Cargo.toml

@@ -50,6 +50,7 @@ datetimes = { path = "../../../lib/data/datetimes" }
 easyenv.workspace = true
 elasticsearch_schema = { path = "../../../schema/database/elasticsearch_schema" }
 enums.workspace = true
+error_utils.workspace = true
 errors.workspace = true
 fal_client.workspace = true
 filesys.workspace = true

crates/service/web/storyteller_web/src/http_server/middleware/error_alerting_middleware/handlers/check_advanced_common_web_error.rs

@@ -1,6 +1,5 @@
+use error_utils::try_error_name::try_error_name;
 use log::{debug, warn};
-use regex::Regex;
-use std::sync::LazyLock;
 
 use pager::client::pager::Pager;
 use pager::notification::notification_details_builder::NotificationDetailsBuilder;
@@ -24,7 +23,7 @@ pub(crate) fn check_advanced_common_web_error(
   }
 
   let maybe_error_name = error.cause()
-      .and_then(|cause| try_error_title(cause));
+      .and_then(|cause| try_error_name(cause));
 
   let title = match maybe_error_name {
     Some(name) => format!("{} on {} {}", name, method, path),
@@ -61,174 +60,3 @@ pub(crate) fn check_advanced_common_web_error(
 
   true
 }
-
-/// Try to extract a human-readable error title from the causal error's Debug
-/// representation. Looks for CamelCase type names like `EnvError::NotUnicode`.
-fn try_error_title(error: &dyn std::error::Error) -> Option<String> {
-  let debug_str = format!("{:?}", error);
-  try_extract_error_name(&debug_str)
-}
-
-/// Regex that matches CamelCase type names with an optional `::Variant` suffix.
-/// E.g. `CommonWebError::InvalidRequest`, `EnvError`, `KinoviError::RequestError`.
-static ERROR_NAME_RE: LazyLock<Regex> = LazyLock::new(|| {
-  Regex::new(r"[A-Z][0-9a-z]+(?:[A-Z][0-9a-z]+)*(?:::[A-Z][0-9a-z]+(?:[A-Z][0-9a-z]+)*)?")
-      .expect("error name regex should compile")
-});
-
-/// Extract the leading CamelCase error name (with optional `::Variant`) from
-/// a Debug-formatted error string. Returns `None` if no match is found.
-///
-/// ```text
-/// "CommonWebError::InvalidRequest(\"bad\")" → Some("CommonWebError::InvalidRequest")
-/// "EnvError::ParseError { reason: \"foo\" }" → Some("EnvError::ParseError")
-/// "just a plain string"                      → None
-/// ```
-fn try_extract_error_name(debug_str: &str) -> Option<String> {
-  ERROR_NAME_RE.find(debug_str)
-      .map(|m| m.as_str().to_string())
-}
-
-#[cfg(test)]
-mod tests {
-  use super::*;
-
-  // --- try_extract_error_name tests ---
-
-  #[test]
-  fn extract_just_error_name() {
-    assert_eq!(
-      try_extract_error_name("JustErrorName"),
-      Some("JustErrorName".to_string()),
-    );
-  }
-
-  #[test]
-  fn extract_error_with_variant_and_string_payload() {
-    assert_eq!(
-      try_extract_error_name(r#"CommonWebError::InvalidRequest("Invalid request")"#),
-      Some("CommonWebError::InvalidRequest".to_string()),
-    );
-  }
-
-  #[test]
-  fn extract_error_with_unit_variant() {
-    assert_eq!(
-      try_extract_error_name("EnvError::NotUnicode"),
-      Some("EnvError::NotUnicode".to_string()),
-    );
-  }
-
-  #[test]
-  fn extract_error_with_struct_payload() {
-    assert_eq!(
-      try_extract_error_name(r#"EnvError::ParseError { reason: "foo" }"#),
-      Some("EnvError::ParseError".to_string()),
-    );
-  }
-
-  #[test]
-  fn extract_error_with_tuple_payload() {
-    assert_eq!(
-      try_extract_error_name("KinoviError::RequestError(asdf)"),
-      Some("KinoviError::RequestError".to_string()),
-    );
-  }
-
-  #[test]
-  fn extract_error_with_nested_errors() {
-    // Should only grab the outermost error name.
-    assert_eq!(
-      try_extract_error_name(
-        "ComplexError::SomeError(SomeError::SomeVariant(SomeInnerError::SomeInnerVariant))"
-      ),
-      Some("ComplexError::SomeError".to_string()),
-    );
-  }
-
-  #[test]
-  fn extract_error_with_struct_containing_nested() {
-    assert_eq!(
-      try_extract_error_name(
-        "WrappedError::Variant { inner: SomeInnerError::SomeInnerVariant }"
-      ),
-      Some("WrappedError::Variant".to_string()),
-    );
-  }
-
-  #[test]
-  fn no_match_for_lowercase_string() {
-    assert_eq!(
-      try_extract_error_name("just a plain error message with no type name"),
-      None,
-    );
-  }
-
-  #[test]
-  fn no_match_for_empty_string() {
-    assert_eq!(try_extract_error_name(""), None);
-  }
-
-  #[test]
-  fn single_word_camel_case() {
-    // A single CamelCase word like "Error" should not match because
-    // the regex requires at least two segments (e.g. "Ab" = A + b).
-    // "Error" = E + rror — "rror" has 4 lowercase chars which is fine.
-    assert_eq!(
-      try_extract_error_name("Error"),
-      Some("Error".to_string()),
-    );
-  }
-
-  // --- try_error_title tests (with real error types) ---
-
-  #[test]
-  fn title_from_io_error() {
-    let err: Box<dyn std::error::Error> = Box::new(
-      std::io::Error::new(std::io::ErrorKind::NotFound, "file not found"),
-    );
-    // io::Error Debug looks like: `Custom { kind: NotFound, error: "file not found" }`
-    // "Custom" doesn't match CamelCase with 2+ segments... but we get what we get.
-    let title = try_error_title(err.as_ref());
-    // The exact output depends on Debug formatting. Just verify it doesn't panic.
-    // Custom has one uppercase + lowercase sequence = "Custom" which matches [A-Z][0-9a-z]+
-    assert!(title.is_some());
-  }
-
-  #[test]
-  fn title_from_serde_json_error() {
-    let err: serde_json::Error = serde_json::from_str::<String>("not json").unwrap_err();
-    let title = try_error_title(&err);
-    // serde_json::Error Debug typically starts with "Error(...)"
-    assert!(title.is_some());
-  }
-
-  /// A simple custom error for testing.
-  #[derive(Debug)]
-  enum TestAppError {
-    DatabaseTimeout,
-    InvalidInput(String),
-  }
-
-  impl std::fmt::Display for TestAppError {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-      write!(f, "{:?}", self)
-    }
-  }
-
-  impl std::error::Error for TestAppError {}
-
-  #[test]
-  fn title_from_custom_unit_variant() {
-    let err = TestAppError::DatabaseTimeout;
-    let title = try_error_title(&err);
-    assert_eq!(title, Some("DatabaseTimeout".to_string()));
-  }
-
-  #[test]
-  fn title_from_custom_tuple_variant() {
-    let err = TestAppError::InvalidInput("bad data".to_string());
-    let title = try_error_title(&err);
-    assert_eq!(title, Some("InvalidInput".to_string()));
-  }
-}