Use trybuild for testing macros

Author: jayvdb

.editorconfig

@@ -46,3 +46,7 @@ indent_style = unset
 [HELP.md]
 max_line_length = 400
 trim_trailing_whitespace = false
+
+[*.stderr]
+indent_size = unset
+max_line_length = 150

.github/workflows/ci.yml

@@ -121,8 +121,6 @@ jobs:
       run: cd butane_test_helper && cargo +stable test --all-features
     - name: Test Core
       run: cd butane_core && cargo +stable test --all-features
-    - name: Test Codegen
-      run: cd butane_codegen && cargo +stable test --all-features
     - name: Test CLI
       run: cd butane_cli && cargo +stable test --all-features
     - name: Test

Cargo.lock

@@ -104,6 +104,10 @@ name = "query"
 path = "query.rs"
 required-features = ["async"]
 
+[[test]]
+name = "trybuild"
+path = "trybuild.rs"
+
 [[test]]
 name = "unmigrate"
 path = "unmigrate.rs"

butane/tests/Cargo.toml

@@ -0,0 +1,8 @@
+// Compile-time tests for FieldType derive macro using trybuild
+
+#[test]
+fn compile_tests() {
+    let t = trybuild::TestCases::new();
+    t.pass("tests/trybuild/pass/*.rs");
+    t.compile_fail("tests/trybuild/fail/*.rs");
+}

butane/tests/trybuild.rs

@@ -0,0 +1,11 @@
+[package]
+name = "butane_codegen-tests"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+butane = { path = "../../", features = ["json"] }
+butane_codegen = { path = "../../butane_codegen" }
+serde = "1.0"
+serde_json = "1.0"

butane/tests/trybuild/Cargo.toml

@@ -0,0 +1,10 @@
+use butane_codegen::FieldType;
+
+// This should fail because enums with data in variants require json feature
+#[derive(FieldType)]
+pub enum ComplexEnum {
+    Variant1(String),
+    Variant2 { field: i32 },
+}
+
+fn main() {}

butane/tests/trybuild/fail/complex_enum_without_json.rs

@@ -0,0 +1,47 @@
+error[E0277]: the trait bound `ComplexEnum: serde::Serialize` is not satisfied
+ --> tests/trybuild/fail/complex_enum_without_json.rs:4:10
+  |
+4 | #[derive(FieldType)]
+  |          ^^^^^^^^^ unsatisfied trait bound
+  |
+help: the trait `Serialize` is not implemented for `ComplexEnum`
+ --> tests/trybuild/fail/complex_enum_without_json.rs:5:1
+  |
+5 | pub enum ComplexEnum {
+  | ^^^^^^^^^^^^^^^^^^^^
+  = note: for local types consider adding `#[derive(serde::Serialize)]` to your `ComplexEnum` type
+  = note: for types from other crates check whether the crate offers a `serde` feature flag
+  = help: the following other types implement trait `Serialize`:
+            &'a T
+            &'a mut T
+            ()
+            (T,)
+            (T0, T1)
+            (T0, T1, T2)
+            (T0, T1, T2, T3)
+            (T0, T1, T2, T3, T4)
+          and $N others
+  = note: required for `&ComplexEnum` to implement `Serialize`
+note: required by a bound in `to_value`
+ --> $CARGO/serde_json-$VERSION/src/value/mod.rs
+  |
+  | pub fn to_value<T>(value: T) -> Result<Value, Error>
+  |        -------- required by a bound in this function
+  | where
+  |     T: Serialize,
+  |        ^^^^^^^^^ required by this bound in `to_value`
+  = note: this error originates in the derive macro `FieldType` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0599]: no variant or associated item named `deserialize` found for enum `ComplexEnum` in the current scope
+ --> tests/trybuild/fail/complex_enum_without_json.rs:4:10
+  |
+4 | #[derive(FieldType)]
+  |          ^^^^^^^^^ variant or associated item not found in `ComplexEnum`
+5 | pub enum ComplexEnum {
+  | -------------------- variant or associated item `deserialize` not found for this enum
+  |
+  = help: items from traits can only be used if the trait is implemented and in scope
+  = note: the following traits define an item `deserialize`, perhaps you need to implement one of them:
+          candidate #1: `Deserialize`
+          candidate #2: `DeserializeSeed`
+  = note: this error originates in the derive macro `FieldType` (in Nightly builds, run with -Z macro-backtrace for more info)

butane/tests/trybuild/fail/complex_enum_without_json.stderr

@@ -0,0 +1,10 @@
+use butane_codegen::FieldType;
+
+// This should fail because the json feature is required for non-newtype structs
+#[derive(FieldType)]
+pub struct Metadata {
+    pub title: String,
+    pub version: i32,
+}
+
+fn main() {}

butane/tests/trybuild/fail/struct_without_json_feature.rs

@@ -0,0 +1,47 @@
+error[E0277]: the trait bound `Metadata: serde::Serialize` is not satisfied
+ --> tests/trybuild/fail/struct_without_json_feature.rs:4:10
+  |
+4 | #[derive(FieldType)]
+  |          ^^^^^^^^^ unsatisfied trait bound
+  |
+help: the trait `Serialize` is not implemented for `Metadata`
+ --> tests/trybuild/fail/struct_without_json_feature.rs:5:1
+  |
+5 | pub struct Metadata {
+  | ^^^^^^^^^^^^^^^^^^^
+  = note: for local types consider adding `#[derive(serde::Serialize)]` to your `Metadata` type
+  = note: for types from other crates check whether the crate offers a `serde` feature flag
+  = help: the following other types implement trait `Serialize`:
+            &'a T
+            &'a mut T
+            ()
+            (T,)
+            (T0, T1)
+            (T0, T1, T2)
+            (T0, T1, T2, T3)
+            (T0, T1, T2, T3, T4)
+          and $N others
+  = note: required for `&Metadata` to implement `Serialize`
+note: required by a bound in `to_value`
+ --> $CARGO/serde_json-$VERSION/src/value/mod.rs
+  |
+  | pub fn to_value<T>(value: T) -> Result<Value, Error>
+  |        -------- required by a bound in this function
+  | where
+  |     T: Serialize,
+  |        ^^^^^^^^^ required by this bound in `to_value`
+  = note: this error originates in the derive macro `FieldType` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0599]: no function or associated item named `deserialize` found for struct `Metadata` in the current scope
+ --> tests/trybuild/fail/struct_without_json_feature.rs:4:10
+  |
+4 | #[derive(FieldType)]
+  |          ^^^^^^^^^ function or associated item not found in `Metadata`
+5 | pub struct Metadata {
+  | ------------------- function or associated item `deserialize` not found for this struct
+  |
+  = help: items from traits can only be used if the trait is implemented and in scope
+  = note: the following traits define an item `deserialize`, perhaps you need to implement one of them:
+          candidate #1: `Deserialize`
+          candidate #2: `DeserializeSeed`
+  = note: this error originates in the derive macro `FieldType` (in Nightly builds, run with -Z macro-backtrace for more info)