Add ability to pass failure message and formatting args to assert_pred, expect_pred macros and add integration tests to verify the failure message.

Also, the matcher syntax of `assert_pred` and `expect_pred` macros is changed to align with `verify_pred`, which is called internally. The previous matcher syntax was overly broad and incorrectly captured additional formatting arguments

PiperOrigin-RevId: 736811118

Author: Googler

googletest/src/assertions.rs

@@ -1412,8 +1412,21 @@ pub use assert_that;
 /// operator.
 #[macro_export]
 macro_rules! assert_pred {
-    ($($content:tt)*) => {
-        match $crate::verify_pred!($($content)*) {
+    ($content:expr $(,)?) => {
+        match $crate::verify_pred!($content) {
+            Ok(_) => {}
+            Err(e) => {
+                // The extra newline before the assertion failure message makes the failure a
+                // bit easier to read when there's some generic boilerplate from the panic.
+                panic!("\n{}", e);
+            }
+        }
+    };
+
+    // w/ format args
+    ($content:expr $(,)?, $($format_args:expr),* $(,)?) => {
+        match $crate::verify_pred!($content)
+            .with_failure_message(|| format!($($format_args),*)) {
             Ok(_) => {}
             Err(e) => {
                 // The extra newline before the assertion failure message makes the failure a
@@ -1525,9 +1538,15 @@ pub use expect_that;
 /// ```
 #[macro_export]
 macro_rules! expect_pred {
-    ($($content:tt)*) => {{
-        $crate::GoogleTestSupport::and_log_failure($crate::verify_pred!($($content)*));
+    ($content:expr $(,)?) => {{
+        $crate::GoogleTestSupport::and_log_failure($crate::verify_pred!($content));
     }};
+    // w/ format args
+    ($content:expr $(,)?, $($format_args:expr),* $(,)?) => {
+        $crate::GoogleTestSupport::and_log_failure($crate::verify_pred!($content)
+            .with_failure_message(|| format!($($format_args),*))
+            )
+    };
 }
 pub use expect_pred;
 

integration_tests/Cargo.toml

@@ -439,4 +439,14 @@ test = false
 [[bin]]
 name = "expect_true_macro_on_false_condition_with_format_args"
 path = "src/expect_true_macro_on_false_condition_with_format_args.rs"
+test = false
+
+[[bin]]
+name = "assert_pred_macro_on_assertion_failure_with_format_args"
+path = "src/assert_pred_macro_on_assertion_failure_with_format_args.rs"
+test = false
+
+[[bin]]
+name = "expect_pred_macro_on_assertion_failure_with_format_args"
+path = "src/expect_pred_macro_on_assertion_failure_with_format_args.rs"
 test = false

integration_tests/src/assert_pred_macro_on_assertion_failure_with_format_args.rs

@@ -0,0 +1,33 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+fn main() {}
+
+#[cfg(test)]
+mod tests {
+    use googletest::prelude::*;
+
+    #[gtest]
+    fn should_fail() {
+        let a = 1;
+        let b = 2;
+        let extra_information = "extra information";
+
+        assert_pred!(eq_predicate(a, b), "assertion failed: {extra_information}")
+    }
+
+    fn eq_predicate(a: i32, b: i32) -> bool {
+        a == b
+    }
+}

integration_tests/src/expect_pred_macro_on_assertion_failure_with_format_args.rs

@@ -0,0 +1,33 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+fn main() {}
+
+#[cfg(test)]
+mod tests {
+    use googletest::prelude::*;
+
+    #[gtest]
+    fn should_fail() {
+        let a = 1;
+        let b = 2;
+        let extra_information = "extra information";
+
+        expect_pred!(eq_predicate(a, b), "assertion failed: {extra_information}")
+    }
+
+    fn eq_predicate(a: i32, b: i32) -> bool {
+        a == b
+    }
+}

integration_tests/src/integration_tests.rs

@@ -2032,7 +2032,7 @@ mod tests {
             "expect_false_macro_on_true_condition_with_format_args",
         )?;
 
-        verify_that!(output, contains_substring(indoc! {"expected false: extra information"}))
+        verify_that!(output, contains_substring("expected false: extra information"))
     }
 
     #[gtest]
@@ -2042,7 +2042,27 @@ mod tests {
             "expect_true_macro_on_false_condition_with_format_args",
         )?;
 
-        verify_that!(output, contains_substring(indoc! {"expected true: extra information"}))
+        verify_that!(output, contains_substring("expected true: extra information"))
+    }
+
+    #[gtest]
+    fn assert_pred_macro_on_assertion_failure_with_format_args_logs_error_when_handled(
+    ) -> Result<()> {
+        let output = run_external_process_in_tests_directory(
+            "assert_pred_macro_on_assertion_failure_with_format_args",
+        )?;
+
+        verify_that!(output, contains_substring("assertion failed: extra information"))
+    }
+
+    #[gtest]
+    fn expect_pred_macro_on_assertion_failure_with_format_args_logs_error_when_handled(
+    ) -> Result<()> {
+        let output = run_external_process_in_tests_directory(
+            "expect_pred_macro_on_assertion_failure_with_format_args",
+        )?;
+
+        verify_that!(output, contains_substring("assertion failed: extra information"))
     }
 
     fn run_external_process_in_tests_directory_with_args(

run_integration_tests.sh

@@ -103,6 +103,8 @@ INTEGRATION_TEST_BINARIES=(
   "expect_panic_with_expected"
   "expect_false_macro_on_true_condition_with_format_args"
   "expect_true_macro_on_false_condition_with_format_args"
+  "assert_pred_macro_on_assertion_failure_with_format_args"
+  "expect_pred_macro_on_assertion_failure_with_format_args"
 )
 
 cargo build