Clarify error messages when using attributes in wrong place

shepmaster · Jul 12, 2019 · fe33842 · fe33842
1 parent d311b5b
commit fe33842
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Showing 3 changed files with 305 additions and 23 deletions.
diff --git a/compatibility-tests/compile-fail/tests/ui/attribute-misuse.rs b/compatibility-tests/compile-fail/tests/ui/attribute-misuse.rs
@@ -0,0 +1,36 @@
+mod enum_misuse {
+    use snafu::Snafu;
+
+    #[derive(Debug, Snafu)]
+    #[snafu(display("display should not work here"))]
+    #[snafu(source(from(XXXX, Box::new)))]
+    #[snafu(source(true))]
+    #[snafu(backtrace)]
+    enum EnumError {
+        #[snafu(display("an error variant"))]
+        #[snafu(source(from(XXXX, Box::new)))]
+        #[snafu(backtrace)]
+        AVariant {
+            #[snafu(display("display should not work here"))]
+            #[snafu(visibility(pub))]
+            a: String,
+        },
+    }
+}
+
+mod struct_misuse {
+    use snafu::Snafu;
+
+    #[derive(Debug, Snafu)]
+    enum UsableError {}
+
+    #[derive(Debug, Snafu)]
+    #[snafu(display("display should not work here"))]
+    #[snafu(source(from(UsableError, Box::new)))]
+    #[snafu(visibility(pub))]
+    #[snafu(source(true))]
+    #[snafu(backtrace)]
+    struct StructError(Box<UsableError>);
+}
+
+fn main() {}
diff --git a/compatibility-tests/compile-fail/tests/ui/attribute-misuse.stderr b/compatibility-tests/compile-fail/tests/ui/attribute-misuse.stderr
@@ -0,0 +1,71 @@
+error: 'display' attribute is only valid on variants of an enum deriving Snafu; attempted to place on this enum:
+ --> $DIR/attribute-misuse.rs:9:10
+  |
+9 |     enum EnumError {
+  |          ^^^^^^^^^
+
+error: 'source(from)' attribute is only valid on individual fields; attempted to place on this enum:
+ --> $DIR/attribute-misuse.rs:9:10
+  |
+9 |     enum EnumError {
+  |          ^^^^^^^^^
+
+error: 'source(bool)' attribute is only valid on individual fields; attempted to place on this enum:
+ --> $DIR/attribute-misuse.rs:9:10
+  |
+9 |     enum EnumError {
+  |          ^^^^^^^^^
+
+error: 'backtrace' attribute is only valid on individual fields; attempted to place on this enum:
+ --> $DIR/attribute-misuse.rs:9:10
+  |
+9 |     enum EnumError {
+  |          ^^^^^^^^^
+
+error: 'source' attribute is only valid on individual fields; attempted to place on this variant:
+  --> $DIR/attribute-misuse.rs:13:9
+   |
+13 |         AVariant {
+   |         ^^^^^^^^
+
+error: 'backtrace' attribute is only valid on individual fields; attempted to place on this variant:
+  --> $DIR/attribute-misuse.rs:13:9
+   |
+13 |         AVariant {
+   |         ^^^^^^^^
+
+error: 'display' attribute is only valid on variants of an enum deriving Snafu; attempted to place on this field:
+  --> $DIR/attribute-misuse.rs:16:13
+   |
+16 |             a: String,
+   |             ^
+
+error: 'visibility' attribute is only valid on an enum deriving Snafu and its variants; attempted to place on this field:
+  --> $DIR/attribute-misuse.rs:16:13
+   |
+16 |             a: String,
+   |             ^
+
+error: 'display' attribute is only valid on variants of an enum deriving Snafu; attempted to place on this struct:
+  --> $DIR/attribute-misuse.rs:33:12
+   |
+33 |     struct StructError(Box<UsableError>);
+   |            ^^^^^^^^^^^
+
+error: 'visibility' attribute is only valid on an enum deriving Snafu and its variants; attempted to place on this struct:
+  --> $DIR/attribute-misuse.rs:33:12
+   |
+33 |     struct StructError(Box<UsableError>);
+   |            ^^^^^^^^^^^
+
+error: 'source(bool)' attribute is only valid on individual fields; attempted to place on this struct:
+  --> $DIR/attribute-misuse.rs:33:12
+   |
+33 |     struct StructError(Box<UsableError>);
+   |            ^^^^^^^^^^^
+
+error: 'backtrace' attribute is only valid on individual fields; attempted to place on this struct:
+  --> $DIR/attribute-misuse.rs:33:12
+   |
+33 |     struct StructError(Box<UsableError>);
+   |            ^^^^^^^^^^^