Fix truncating invalid UTF-8 strings

Author: Jordi Freixa Serrabassa

src/Type/Constant/ConstantStringType.php

@@ -61,8 +61,14 @@ function (): string {
 					return var_export($this->value, true);
 				}
 
+				try {
+					$truncatedValue = \Nette\Utils\Strings::truncate($this->value, self::DESCRIBE_LIMIT);
+				} catch (\Nette\Utils\RegexpException $e) {
+					$truncatedValue = substr($this->value, 0, self::DESCRIBE_LIMIT) . "\u{2026}";
+				}
+
 				return var_export(
-					\Nette\Utils\Strings::truncate($this->value, self::DESCRIBE_LIMIT),
+					$truncatedValue,
 					true
 				);
 			},

tests/PHPStan/Type/Constant/ConstantStringTypeTest.php

@@ -148,4 +148,14 @@ public function testGeneralize(): void
 		$this->assertSame('class-string', (new ConstantStringType('NonexistentClass', true))->generalize()->describe(VerbosityLevel::precise()));
 	}
 
+	public function testTextInvalidEncoding(): void
+	{
+		$this->assertSame("'\xc3Lorem ipsum dolor s\u{2026}'", (new ConstantStringType("\xc3Lorem ipsum dolor sit"))->describe(VerbosityLevel::value()));
+	}
+
+	public function testShortTextInvalidEncoding(): void
+	{
+		$this->assertSame("'\xc3Lorem ipsum dolor'", (new ConstantStringType("\xc3Lorem ipsum dolor"))->describe(VerbosityLevel::value()));
+	}
+
 }