Tests for types::fmt module

Author: luisfi-dev

impl/src/types/fmt/input.rs

@@ -121,3 +121,95 @@ impl ToTokens for EnumVariantFormatInput {
         });
     }
 }
+
+#[cfg(test)]
+#[allow(clippy::expect_used)]
+mod tests {
+    use super::*;
+
+    use quote::quote;
+
+    #[test]
+    fn struct_format_input_requires_initial_lit_str() {
+        let empty_stream_res = syn::parse2::<StructFormatInput>(quote! {});
+        let err = empty_stream_res.expect_err(
+            "empty stream was parsed successfully as StructFormatInput",
+        );
+        assert_eq!(
+            err.to_string(),
+            "unexpected end of input, expected string literal"
+        );
+    }
+
+    #[test]
+    fn struct_format_input_requires_initial_arg_to_be_lit_str() {
+        let empty_stream_res =
+            syn::parse2::<StructFormatInput>(quote! { true });
+        let err = empty_stream_res.expect_err(
+            "stream `true` was parsed successfully as StructFormatInput",
+        );
+        assert_eq!(err.to_string(), "expected string literal");
+    }
+
+    #[test]
+    fn struct_format_input_rejects_unexpected_token_after_lit_str() {
+        let empty_stream_res =
+            syn::parse2::<StructFormatInput>(quote! { "format string" 5 });
+        let err = empty_stream_res.expect_err(
+            "stream `\"format string\" 5` was parsed successfully as StructFormatInput",
+        );
+        assert_eq!(err.to_string(), "unexpected token after string literal");
+    }
+
+    #[test]
+    fn struct_format_input_parses_lit_str_with_trailing_comma() {
+        let empty_stream_res =
+            syn::parse2::<StructFormatInput>(quote! { "format string", });
+        let format_input = empty_stream_res.expect(
+            "stream `\"format string\",` could not be parsed as StructFormatInput",
+        );
+        assert_eq!(format_input.lit_str.value(), "format string");
+    }
+
+    #[test]
+    fn enum_variant_format_input_requires_initial_lit_str() {
+        let empty_stream_res = syn::parse2::<EnumVariantFormatInput>(quote! {});
+        let err = empty_stream_res.expect_err(
+            "empty stream was parsed successfully as EnumVariantFormatInput",
+        );
+        assert_eq!(
+            err.to_string(),
+            "unexpected end of input, expected string literal"
+        );
+    }
+
+    #[test]
+    fn enum_variant_format_input_requires_initial_arg_to_be_lit_str() {
+        let empty_stream_res =
+            syn::parse2::<EnumVariantFormatInput>(quote! { true });
+        let err = empty_stream_res.expect_err(
+            "stream `true` was parsed successfully as EnumVariantFormatInput",
+        );
+        assert_eq!(err.to_string(), "expected string literal");
+    }
+
+    #[test]
+    fn enum_variant_format_input_rejects_unexpected_token_after_lit_str() {
+        let empty_stream_res =
+            syn::parse2::<EnumVariantFormatInput>(quote! { "format string" 5 });
+        let err = empty_stream_res.expect_err(
+            "stream `\"format string\" 5` was parsed successfully as EnumVariantFormatInput",
+        );
+        assert_eq!(err.to_string(), "unexpected token after string literal");
+    }
+
+    #[test]
+    fn enum_variant_format_input_parses_lit_str_with_trailing_comma() {
+        let empty_stream_res =
+            syn::parse2::<EnumVariantFormatInput>(quote! { "format string", });
+        let format_input = empty_stream_res.expect(
+            "stream `\"format string\",` could not be parsed as EnumVariantFormatInput",
+        );
+        assert_eq!(format_input.lit_str.value(), "format string");
+    }
+}

impl/src/types/fmt/mod.rs

@@ -202,3 +202,89 @@ impl ToTokens for FormatData {
         }
     }
 }
+
+#[cfg(test)]
+#[allow(clippy::expect_used)]
+mod tests {
+    use super::*;
+
+    use quote::quote;
+
+    #[test]
+    fn struct_format_data_requires_display_attr() {
+        let derive_input =
+            syn::parse2::<DeriveInput>(quote! { struct CustomType; })
+                .expect("malformed test stream");
+        let err = FormatData::new(&derive_input).expect_err(
+            "stream without display attr was parsed successfully as FormatData",
+        );
+        assert_eq!(
+            err.to_string(),
+            "missing `display` attribute for struct with `#[derive(Error)]`"
+        );
+    }
+
+    #[test]
+    fn struct_format_data_requires_list_form_for_display_attr() {
+        let derive_input = syn::parse2::<DeriveInput>(
+            quote! { #[display] struct CustomType; },
+        )
+        .expect("malformed test stream");
+        let err = FormatData::new(&derive_input).expect_err(
+            "stream with path display attr was parsed successfully as FormatData",
+        );
+        assert_eq!(
+            err.to_string(),
+            "expected `display` to be a list attribute: `#[display(\"template...\")]`"
+        );
+    }
+
+    #[test]
+    fn enum_format_data_requires_display_attr() {
+        let derive_input =
+            syn::parse2::<DeriveInput>(quote! { enum CustomType { One, Two } })
+                .expect("malformed test stream");
+        let err = FormatData::new(&derive_input).expect_err(
+            "stream without display attr was parsed successfully as FormatData",
+        );
+        assert_eq!(
+            err.to_string(),
+            "missing `display` attribute for enum with `#[derive(Error)]`\nadd a `display` attribute to at least the whole enum or to all of its variants"
+        );
+    }
+
+    #[test]
+    fn enum_format_data_requires_list_form_for_display_attr() {
+        let derive_input = syn::parse2::<DeriveInput>(
+            quote! { #[display] enum CustomType { One, Two } },
+        )
+        .expect("malformed test stream");
+        let err = FormatData::new(&derive_input).expect_err(
+            "stream with path display attr was parsed successfully as FormatData",
+        );
+        assert_eq!(
+            err.to_string(),
+            "expected `display` to be a list attribute: `#[display(\"template...\")]`"
+        );
+    }
+
+    #[test]
+    fn enum_format_data_requires_list_form_for_display_attr_on_every_variant() {
+        let derive_input = syn::parse2::<DeriveInput>(quote! {
+            enum CustomType {
+                #[display]
+                One,
+                #[display]
+                Two
+            }
+        })
+        .expect("malformed test stream");
+        let err = FormatData::new(&derive_input).expect_err(
+            "stream with path display attr was parsed successfully as FormatData",
+        );
+        assert_eq!(
+            err.to_string(),
+            "expected `display` to be a list attribute: `#[display(\"template...\")]`"
+        );
+    }
+}

tests/src/lib.rs

@@ -1,14 +1 @@
-pub fn add(left: u64, right: u64) -> u64 {
-    left + right
-}
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
-}