tests/acceptance: Introduce tesseract_ocr() helper

We are going to reuse the tesseract OCR code.
Create a new tesseract_ocr() helper and use it.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20201021105035.2477784-5-f4bug@amsat.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

tests/acceptance/machine_m68k_nextcube.py

@@ -7,13 +7,11 @@
 
 import os
 import time
-import logging
 
 from avocado_qemu import Test
 from avocado import skipUnless
-from avocado.utils import process
 
-from tesseract_utils import tesseract_available
+from tesseract_utils import tesseract_available, tesseract_ocr
 
 PIL_AVAILABLE = True
 try:
@@ -61,12 +59,8 @@ class NextCubeMachine(Test):
     def test_bootrom_framebuffer_ocr_with_tesseract_v3(self):
         screenshot_path = os.path.join(self.workdir, "dump.ppm")
         self.check_bootrom_framebuffer(screenshot_path)
-
-        console_logger = logging.getLogger('console')
-        text = process.run("tesseract %s stdout" % screenshot_path).stdout_text
-        for line in text.split('\n'):
-            if len(line):
-                console_logger.debug(line)
+        lines = tesseract_ocr(screenshot_path, tesseract_version=3)
+        text = '\n'.join(lines)
         self.assertIn('Backplane', text)
         self.assertIn('Ethernet address', text)
 
@@ -77,13 +71,8 @@ class NextCubeMachine(Test):
     def test_bootrom_framebuffer_ocr_with_tesseract_v4(self):
         screenshot_path = os.path.join(self.workdir, "dump.ppm")
         self.check_bootrom_framebuffer(screenshot_path)
-
-        console_logger = logging.getLogger('console')
-        proc = process.run("tesseract --oem 1 %s stdout" % screenshot_path)
-        text = proc.stdout_text
-        for line in text.split('\n'):
-            if len(line):
-                console_logger.debug(line)
+        lines = tesseract_ocr(screenshot_path, tesseract_version=4)
+        text = '\n'.join(lines)
         self.assertIn('Testing the FPU, SCC', text)
         self.assertIn('System test failed. Error code', text)
         self.assertIn('Boot command', text)

tests/acceptance/tesseract_utils.py

@@ -6,7 +6,9 @@
 # later. See the COPYING file in the top-level directory.
 
 import re
+import logging
 
+from avocado.utils import process
 from avocado.utils.path import find_command, CmdNotFoundError
 
 def tesseract_available(expected_version):
@@ -26,3 +28,19 @@ def tesseract_available(expected_version):
         return False
     # now this is guaranteed to be a digit
     return int(match.groups()[0]) == expected_version
+
+
+def tesseract_ocr(image_path, tesseract_args='', tesseract_version=3):
+    console_logger = logging.getLogger('tesseract')
+    console_logger.debug(image_path)
+    if tesseract_version == 4:
+        tesseract_args += ' --oem 1'
+    proc = process.run("tesseract {} {} stdout".format(tesseract_args,
+                                                       image_path))
+    lines = []
+    for line in proc.stdout_text.split('\n'):
+        sline = line.strip()
+        if len(sline):
+            console_logger.debug(sline)
+            lines += [sline]
+    return lines