Simplify failure description returned by PHPMatcherConstraint

src/PHPUnit/PHPMatcherConstraint.php

@@ -5,6 +5,7 @@
 namespace Coduo\PHPMatcher\PHPUnit;
 
 use Coduo\PHPMatcher\Backtrace;
+use Coduo\PHPMatcher\Backtrace\VoidBacktrace;
 use Coduo\PHPMatcher\PHPMatcher;
 use PHPUnit\Framework\Constraint\Constraint;
 use PHPUnit\Util\Json;
@@ -42,10 +43,13 @@ public function toString() : string
 
     protected function failureDescription($other) : string
     {
-        return parent::failureDescription($other)
-            . "\nPattern: " . $this->exporter()->export($this->pattern)
-            . "\nError: " . $this->matcher->error()
-            . "\nBacktrace: \n" . $this->matcher->backtrace();
+        $errorDescription = $this->matcher->error() ?: 'Value does not match given pattern';
+        $backtrace = $this->matcher->backtrace();
+
+        return $backtrace instanceof VoidBacktrace
+            ? $errorDescription
+            : $errorDescription
+                . "\nBacktrace:\n" . $this->matcher->backtrace();
     }
 
     protected function matches($value) : bool

tests/PHPUnit/PHPMatcherAssertionsTest.php

@@ -25,11 +25,7 @@ public function test_it_throws_an_expectation_failed_exception_if_a_value_does_n
         } catch (\Exception $e) {
             $this->assertSame(
                 <<<'ERROR'
-Failed asserting that '{"foo":"bar"}' matches given pattern.
-Pattern: '{"foo": "@integer@"}'
-Error: Value "bar" does not match pattern "@integer@" at path: "[foo]"
-Backtrace: 
-Empty.
+Failed asserting that Value "bar" does not match pattern "@integer@" at path: "[foo]".
 ERROR,
                 $e->getMessage()
             );
@@ -45,10 +41,8 @@ public function test_it_throws_an_expectation_failed_exception_if_a_value_does_n
         } catch (\Exception $e) {
             $this->assertSame(
                 <<<ERROR
-Failed asserting that '{"foo":"bar"}' matches given pattern.
-Pattern: '{"foo": "@integer@"}'
-Error: Value "bar" does not match pattern "@integer@" at path: "[foo]"
-Backtrace: 
+Failed asserting that Value "bar" does not match pattern "@integer@" at path: "[foo]"
+Backtrace:
 #1 Matcher Coduo\PHPMatcher\Matcher matching value "{"foo":"bar"}" with "{"foo":"@integer@"}" pattern
 #2 Matcher Coduo\PHPMatcher\Matcher\ChainMatcher (all) matching value "{"foo":"bar"}" with "{"foo":"@integer@"}" pattern
 #3 Matcher Coduo\PHPMatcher\Matcher\ChainMatcher (scalars) can match pattern "{"foo":"@integer@"}"
@@ -150,7 +144,7 @@ public function test_it_creates_a_constraint_for_stubs() : void
          *  #...
          *  #35 Matcher Coduo\PHPMatcher\Matcher error: integer "42" is not a valid string.
          */
-        $this->expectExceptionMessageMatches("/Expectation failed for method name is \"getTitle\" when invoked zero or more times\nParameter 0 for invocation stdClass::getTitle\(42\) does not match expected value.\nFailed asserting that 42 matches given pattern.\nPattern: '@string@'\nError: integer \"42\" is not a valid string.\nBacktrace: \n(.*)/");
+        $this->expectExceptionMessageMatches("/Expectation failed for method name is \"getTitle\" when invoked zero or more times\nParameter 0 for invocation stdClass::getTitle\(42\) does not match expected value.\nFailed asserting that integer \"42\" is not a valid string../");
 
         $mock = $this->getMockBuilder('stdClass')
             ->setMethods(['getTitle'])

tests/PHPUnit/PHPMatcherConstraintTest.php

@@ -34,7 +34,7 @@ public function test_it_returns_false_if_a_value_does_not_match_the_pattern() :
     public function test_it_sets_a_failure_description_if_not_given() : void
     {
         $this->expectException(AssertionFailedError::class);
-        $this->expectExceptionMessageMatches('/Failed asserting that 42 matches given pattern(.*)/');
+        $this->expectExceptionMessageMatches('/Failed asserting that integer "42" is not a valid string../');
 
         $constraint = new PHPMatcherConstraint('@string@');
 

tests/PHPUnit/PHPMatcherTestCaseTest.php

@@ -17,15 +17,15 @@ public function test_it_asserts_if_a_value_matches_the_pattern() : void
     public function test_it_throws_an_expectation_failed_exception_if_a_value_does_not_match_the_pattern() : void
     {
         $this->expectException(AssertionFailedError::class);
-        $this->expectExceptionMessageMatches("/Failed asserting that '{\"foo\":\"bar\"}' matches given pattern(.*)/");
+        $this->expectExceptionMessageMatches('/Failed asserting that Value "bar" does not match pattern "@integer@" at path: "\\[foo\\]"./');
 
         $this->assertMatchesPattern('{"foo": "@integer@"}', \json_encode(['foo' => 'bar']));
     }
 
     public function test_it_creates_a_constraint_for_stubs() : void
     {
         $this->expectException(AssertionFailedError::class);
-        $this->expectExceptionMessageMatches('/Failed asserting that 42 matches given pattern(.*)/');
+        $this->expectExceptionMessageMatches('/Failed asserting that integer "42" is not a valid string../');
 
         $mock = $this->getMockBuilder('stdClass')
             ->setMethods(['getTitle'])