Fix rendering of match explanations inside the some, ok and err matchers.

This changes the aforementioned matchers to use the `Description` API to construct match explanations rather than constructing a `String` directly and converting it to a `Description`. Doing this fixes the formatting when the nested matchers is generated by `all!` or `any!`.

Fixed #325

Author: hovinen

googletest/src/matchers/err_matcher.rs

@@ -61,7 +61,9 @@ impl<T: Debug, E: Debug, InnerMatcherT: Matcher<ActualT = E>> Matcher
 
     fn explain_match(&self, actual: &Self::ActualT) -> Description {
         match actual {
-            Err(e) => format!("which is an error {}", self.inner.explain_match(e)).into(),
+            Err(e) => {
+                Description::new().text("which is an error").nested(self.inner.explain_match(e))
+            }
             Ok(_) => "which is a success".into(),
         }
     }
@@ -128,7 +130,8 @@ mod tests {
                     Value of: Err::<i32, i32>(1)
                     Expected: is an error which is equal to 2
                     Actual: Err(1),
-                      which is an error which isn't equal to 2
+                      which is an error
+                        which isn't equal to 2
                 "
             ))))
         )

googletest/src/matchers/ok_matcher.rs

@@ -61,7 +61,9 @@ impl<T: Debug, E: Debug, InnerMatcherT: Matcher<ActualT = T>> Matcher
 
     fn explain_match(&self, actual: &Self::ActualT) -> Description {
         match actual {
-            Ok(o) => format!("which is a success {}", self.inner.explain_match(o)).into(),
+            Ok(o) => {
+                Description::new().text("which is a success").nested(self.inner.explain_match(o))
+            }
             Err(_) => "which is an error".into(),
         }
     }
@@ -130,7 +132,8 @@ mod tests {
                     Value of: Ok::<i32, i32>(1)
                     Expected: is a success containing a value, which is equal to 2
                     Actual: Ok(1),
-                      which is a success which isn't equal to 2
+                      which is a success
+                        which isn't equal to 2
                 "
             ))))
         )

googletest/src/matchers/some_matcher.rs

@@ -56,7 +56,9 @@ impl<T: Debug, InnerMatcherT: Matcher<ActualT = T>> Matcher for SomeMatcher<T, I
 
     fn explain_match(&self, actual: &Option<T>) -> Description {
         match (self.matches(actual), actual) {
-            (_, Some(t)) => format!("which has a value {}", self.inner.explain_match(t)).into(),
+            (_, Some(t)) => {
+                Description::new().text("which has a value").nested(self.inner.explain_match(t))
+            }
             (_, None) => "which is None".into(),
         }
     }
@@ -119,7 +121,8 @@ mod tests {
                     Value of: Some(2)
                     Expected: has a value which is equal to 1
                     Actual: Some(2),
-                      which has a value which isn't equal to 1
+                      which has a value
+                        which isn't equal to 1
                 "
             ))))
         )
@@ -150,15 +153,15 @@ mod tests {
     fn some_explain_match_with_some_success() -> Result<()> {
         verify_that!(
             some(eq(1)).explain_match(&Some(1)),
-            displays_as(eq("which has a value which is equal to 1"))
+            displays_as(eq("which has a value\n  which is equal to 1"))
         )
     }
 
     #[test]
     fn some_explain_match_with_some_fail() -> Result<()> {
         verify_that!(
             some(eq(1)).explain_match(&Some(2)),
-            displays_as(eq("which has a value which isn't equal to 1"))
+            displays_as(eq("which has a value\n  which isn't equal to 1"))
         )
     }
 }

googletest/tests/all_matcher_test.rs

@@ -89,3 +89,67 @@ fn all_multiple_failed_assertions() -> Result<()> {
         ))))
     )
 }
+
+#[test]
+fn formats_error_message_correctly_when_all_is_inside_some() -> Result<()> {
+    let value = Some(4);
+    let result = verify_that!(value, some(all![eq(1), eq(2), eq(3)]));
+    verify_that!(
+        result,
+        err(displays_as(contains_substring(indoc!(
+            "
+            Value of: value
+            Expected: has a value which has all the following properties:
+              * is equal to 1
+              * is equal to 2
+              * is equal to 3
+            Actual: Some(4),
+              which has a value
+                * which isn't equal to 1
+                * which isn't equal to 2
+                * which isn't equal to 3"
+        ))))
+    )
+}
+
+#[test]
+fn formats_error_message_correctly_when_all_is_inside_ok() -> Result<()> {
+    let value: std::result::Result<i32, std::io::Error> = Ok(4);
+    let result = verify_that!(value, ok(all![eq(1), eq(2), eq(3)]));
+    verify_that!(
+        result,
+        err(displays_as(contains_substring(indoc!(
+            "
+            Value of: value
+            Expected: is a success containing a value, which has all the following properties:
+              * is equal to 1
+              * is equal to 2
+              * is equal to 3
+            Actual: Ok(4),
+              which is a success
+                * which isn't equal to 1
+                * which isn't equal to 2
+                * which isn't equal to 3"
+        ))))
+    )
+}
+
+#[test]
+fn formats_error_message_correctly_when_all_is_inside_err() -> Result<()> {
+    let value: std::result::Result<(), &'static str> = Err("An error");
+    let result = verify_that!(value, err(all![starts_with("Not"), ends_with("problem")]));
+    verify_that!(
+        result,
+        err(displays_as(contains_substring(indoc!(
+            r#"
+            Value of: value
+            Expected: is an error which has all the following properties:
+              * starts with prefix "Not"
+              * ends with suffix "problem"
+            Actual: Err("An error"),
+              which is an error
+                * which does not start with "Not"
+                * which does not end with "problem""#
+        ))))
+    )
+}

googletest/tests/any_matcher_test.rs

@@ -89,3 +89,67 @@ fn all_multiple_failed_assertions() -> Result<()> {
         ))))
     )
 }
+
+#[test]
+fn formats_error_message_correctly_when_any_is_inside_some() -> Result<()> {
+    let value = Some(4);
+    let result = verify_that!(value, some(any![eq(1), eq(2), eq(3)]));
+    verify_that!(
+        result,
+        err(displays_as(contains_substring(indoc!(
+            "
+            Value of: value
+            Expected: has a value which has at least one of the following properties:
+              * is equal to 1
+              * is equal to 2
+              * is equal to 3
+            Actual: Some(4),
+              which has a value
+                * which isn't equal to 1
+                * which isn't equal to 2
+                * which isn't equal to 3"
+        ))))
+    )
+}
+
+#[test]
+fn formats_error_message_correctly_when_any_is_inside_ok() -> Result<()> {
+    let value: std::result::Result<i32, std::io::Error> = Ok(4);
+    let result = verify_that!(value, ok(any![eq(1), eq(2), eq(3)]));
+    verify_that!(
+        result,
+        err(displays_as(contains_substring(indoc!(
+            "
+            Value of: value
+            Expected: is a success containing a value, which has at least one of the following properties:
+              * is equal to 1
+              * is equal to 2
+              * is equal to 3
+            Actual: Ok(4),
+              which is a success
+                * which isn't equal to 1
+                * which isn't equal to 2
+                * which isn't equal to 3"
+        ))))
+    )
+}
+
+#[test]
+fn formats_error_message_correctly_when_any_is_inside_err() -> Result<()> {
+    let value: std::result::Result<(), &'static str> = Err("An error");
+    let result = verify_that!(value, err(any![starts_with("Not"), ends_with("problem")]));
+    verify_that!(
+        result,
+        err(displays_as(contains_substring(indoc!(
+            r#"
+            Value of: value
+            Expected: is an error which has at least one of the following properties:
+              * starts with prefix "Not"
+              * ends with suffix "problem"
+            Actual: Err("An error"),
+              which is an error
+                * which does not start with "Not"
+                * which does not end with "problem""#
+        ))))
+    )
+}