Do not accept empty OCRmyPDF results #79

.gitignore

@@ -5,4 +5,5 @@ coverage*.html
 coverage_html
 build
 .phpunit.result.cache
-*.cov
+*.cov
+coverage

lib/OcrProcessors/PdfOcrProcessor.php

@@ -50,15 +50,24 @@ public function ocrFile(string $fileContent): string {
 		$stdErr = $this->command->getStdErr();
 		$exitCode = $this->command->getExitCode();
 
-		if ($success) {
-			if ($stdErr !== '' || $errorOutput !== '') {
-				// Log warning if ocrmypdf wrote a warning to the stderr
-				$this->logger->warning('OCRmyPDF succeeded with warning(s): {stdErr}, {errorOutput}', [$stdErr, $errorOutput]);
-			}
+		if (!$success) {
+			throw new OcrNotPossibleException('OCRmyPDF exited abnormally with exit-code ' . $exitCode . '. Message: ' . $errorOutput . ' ' . $stdErr);
+		}
+
+		if ($stdErr !== '' || $errorOutput !== '') {
+			// Log warning if ocrmypdf wrote a warning to the stderr
+			$this->logger->warning('OCRmyPDF succeeded with warning(s): {stdErr}, {errorOutput}', [
+				'stdErr' => $stdErr,
+				'errorOutput' => $errorOutput
+			]);
+		}
+
+		$ocrOutput = $this->command->getOutput();
 
-			return $this->command->getOutput();
+		if (!$ocrOutput) {
+			throw new OcrNotPossibleException('OCRmyPDF did not produce any output');
 		}
 
-		throw new OcrNotPossibleException('OCRmyPDF exited abnormally with exit-code ' . $exitCode . '. Message: ' . $errorOutput . ' ' . $stdErr);
+		return $ocrOutput;
 	}
 }

tests/Unit/OcrProcessors/PdfOcrProcessorTest.php

@@ -107,22 +107,54 @@ public function testLogsWarningIfOcrMyPdfSucceedsWithWarningOutput() {
 			->willReturn(true);
 		$this->command->expects($this->once())
 			->method('getError')
-			->willReturn('error');
+			->willReturn('getErrorOutput');
 		$this->command->expects($this->once())
 			->method('getStdErr')
-			->willReturn('stdErr');
+			->willReturn('stdErrOutput');
+		$this->command->expects($this->once())
+			->method('getOutput')
+			->willReturn('someOcrFileContent');
 		$this->logger->expects($this->once())
 			->method('warning')
 			->with(
-				$this->stringStartsWith('OCRmyPDF succeeded with warning(s):'),
+				'OCRmyPDF succeeded with warning(s): {stdErr}, {errorOutput}',
 				$this->callback(function ($paramsArray) {
 					return is_array($paramsArray) &&
 							count($paramsArray) === 2 &&
-							$paramsArray[0] === 'stdErr' &&
-							$paramsArray[1] === 'error';
+							$paramsArray['stdErr'] === 'stdErrOutput' &&
+							$paramsArray['errorOutput'] === 'getErrorOutput';
 				}));
 
 		$processor = new PdfOcrProcessor($this->command, $this->logger);
 		$processor->ocrFile('someContent');
 	}
+
+	public function testThrowsErrorIfOcrFileWasEmpty() {
+		$this->command->expects($this->once())
+			->method('execute')
+			->willReturn(true);
+		$this->command->expects($this->once())
+			->method('getError')
+			->willReturn('error');
+		$this->command->expects($this->once())
+			->method('getStdErr')
+			->willReturn('stdErr');
+		$this->command->expects($this->once())
+			->method('getOutput')
+			->willReturn('');
+
+
+		$thrown = false;
+		$processor = new PdfOcrProcessor($this->command, $this->logger);
+
+		try {
+			$processor->ocrFile('someContent');
+		} catch (\Throwable $t) {
+			$thrown = true;
+			$this->assertInstanceOf(OcrNotPossibleException::class, $t);
+			$this->assertEquals('OCRmyPDF did not produce any output', $t->getMessage());
+		}
+
+		$this->assertTrue($thrown);
+	}
 }