Avoid poisoned Lazy instance by moving potential panic outside

Author: sharkdp

numbat/src/interpreter.rs

@@ -13,7 +13,7 @@ use thiserror::Error;
 
 pub use crate::value::Value;
 
-#[derive(Debug, Error, PartialEq, Eq)]
+#[derive(Debug, Clone, Error, PartialEq, Eq)]
 pub enum RuntimeError {
     #[error("Division by zero")]
     DivisionByZero,

numbat/src/lib.rs

@@ -71,7 +71,7 @@ use unit_registry::UnitMetadata;
 use crate::prefix_parser::PrefixParserResult;
 use crate::unicode_input::UNICODE_INPUT;
 
-#[derive(Debug, Error)]
+#[derive(Debug, Clone, Error)]
 pub enum NumbatError {
     #[error("{0}")]
     ResolverError(ResolverError),

numbat/src/typechecker.rs

@@ -25,7 +25,7 @@ use num_traits::{CheckedAdd, CheckedDiv, CheckedMul, CheckedSub, FromPrimitive,
 use thiserror::Error;
 use unicode_width::UnicodeWidthStr;
 
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct IncompatibleDimensionsError {
     pub span_operation: Span,
     pub operation: String,
@@ -200,7 +200,7 @@ impl fmt::Display for IncompatibleDimensionsError {
 
 impl Error for IncompatibleDimensionsError {}
 
-#[derive(Debug, Error, PartialEq, Eq)]
+#[derive(Debug, Clone, Error, PartialEq, Eq)]
 pub enum TypeCheckError {
     #[error("Unknown identifier '{1}'.")]
     UnknownIdentifier(Span, String, Option<String>),

numbat/tests/common.rs

@@ -1,6 +1,6 @@
 use std::path::Path;
 
-use numbat::{module_importer::FileSystemImporter, resolver::CodeSource, Context};
+use numbat::{module_importer::FileSystemImporter, resolver::CodeSource, Context, NumbatError};
 use once_cell::sync::Lazy;
 
 pub fn get_test_context_without_prelude() -> Context {
@@ -17,14 +17,12 @@ pub fn get_test_context_without_prelude() -> Context {
 }
 
 pub fn get_test_context() -> Context {
-    static CONTEXT: Lazy<Context> = Lazy::new(|| {
+    static CONTEXT: Lazy<Result<Context, NumbatError>> = Lazy::new(|| {
         let mut context = get_test_context_without_prelude();
 
-        let _ = context
-            .interpret("use prelude", CodeSource::Internal)
-            .expect("Error while running prelude");
-        context
+        let _ = context.interpret("use prelude", CodeSource::Internal)?;
+        Ok(context)
     });
 
-    CONTEXT.clone()
+    CONTEXT.clone().unwrap()
 }