Add compile tests for crate = "..."

derive_builder/tests/compile-fail/crate_root.rs

@@ -0,0 +1,16 @@
+#[macro_use]
+extern crate derive_builder;
+
+// This is a stand-in for any bad crate directive
+mod empty {}
+
+#[derive(Builder)]
+// It would be nice if the "failed to resolve" errors would identify `"empty"` as the error span,
+// but doing so would require rewriting a lot of the code generation to use the crate_root span
+// for the full path of the thing being imported, and that doesn't seem worth the code churn.
+#[builder(crate = "empty")]
+struct BadCrate {
+    lorem: String,
+}
+
+fn main() {}

derive_builder/tests/compile-fail/crate_root.stderr

@@ -0,0 +1,97 @@
+error[E0433]: failed to resolve: could not find `export` in `empty`
+ --> tests/compile-fail/crate_root.rs:7:10
+  |
+7 | #[derive(Builder)]
+  |          ^^^^^^^ could not find `export` in `empty`
+  |
+  = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error[E0433]: failed to resolve: could not find `export` in `empty`
+ --> tests/compile-fail/crate_root.rs:7:10
+  |
+7 | #[derive(Builder)]
+  |          ^^^^^^^ not found in `empty::export::core::option`
+  |
+  = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider importing this enum
+  |
+5 | use derive_builder::export::core::option::Option;
+  |
+
+error[E0433]: failed to resolve: could not find `export` in `empty`
+ --> tests/compile-fail/crate_root.rs:7:10
+  |
+7 | #[derive(Builder)]
+  |          ^^^^^^^ not found in `empty::export::core::clone`
+  |
+  = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider importing this trait
+  |
+5 | use derive_builder::export::core::clone::Clone;
+  |
+
+error[E0433]: failed to resolve: could not find `export` in `empty`
+ --> tests/compile-fail/crate_root.rs:7:10
+  |
+7 | #[derive(Builder)]
+  |          ^^^^^^^ not found in `empty::export::core::result`
+  |
+  = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider importing one of these items
+  |
+5 | use derive_builder::export::core::fmt::Result;
+  |
+5 | use derive_builder::export::core::io::Result;
+  |
+5 | use derive_builder::export::core::result::Result;
+  |
+5 | use derive_builder::export::core::thread::Result;
+  |
+
+error[E0433]: failed to resolve: could not find `export` in `empty`
+ --> tests/compile-fail/crate_root.rs:7:10
+  |
+7 | #[derive(Builder)]
+  |          ^^^^^^^ not found in `empty::export::core::convert`
+  |
+  = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider importing this trait
+  |
+5 | use derive_builder::export::core::convert::Into;
+  |
+
+error[E0433]: failed to resolve: could not find `UninitializedFieldError` in `empty`
+ --> tests/compile-fail/crate_root.rs:7:10
+  |
+7 | #[derive(Builder)]
+  |          ^^^^^^^ not found in `empty`
+  |
+  = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider importing this struct
+  |
+5 | use derive_builder::UninitializedFieldError;
+  |
+
+error[E0433]: failed to resolve: could not find `export` in `empty`
+ --> tests/compile-fail/crate_root.rs:7:10
+  |
+7 | #[derive(Builder)]
+  |          ^^^^^^^ not found in `empty::export::core::default`
+  |
+  = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider importing this trait
+  |
+5 | use derive_builder::export::core::default::Default;
+  |
+
+error[E0412]: cannot find type `UninitializedFieldError` in module `empty`
+ --> tests/compile-fail/crate_root.rs:7:10
+  |
+7 | #[derive(Builder)]
+  |          ^^^^^^^ not found in `empty`
+  |
+  = note: this error originates in the derive macro `Builder` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: consider importing this struct
+  |
+5 | use derive_builder::UninitializedFieldError;
+  |

derive_builder/tests/run-pass/crate_alias.rs

@@ -0,0 +1,24 @@
+//! Test that an alias of derive_builder is valid in #[builder(crate = "...")]
+//!
+//! This test is imperfect, as it still passes without setting `crate = "..."`.
+//! This is likely because `derive_builder` is automatically present in 2018
+//! without needing the extern crate line.
+//!
+//! The test will fail if an incorrect alias is used, so it adds limited value.
+
+#[macro_use]
+extern crate derive_builder as db;
+
+#[derive(Builder)]
+#[builder(crate = "db")]
+struct AliasedCrate {
+    #[builder(setter(into))]
+    lorem: String,
+}
+
+fn main() {
+    AliasedCrateBuilder::default()
+        .lorem("hello")
+        .build()
+        .unwrap();
+}