Use gflanguages module to check sample rendering

com.google.fonts/check/metadata/can_render_samples

Check that the fonts can render the sample texts for all languages specified on METADATA.pb, by using the new `gflanguages` module.
(issue #3605)

CHANGELOG.md

@@ -6,6 +6,10 @@ A more detailed list of changes is available in the corresponding milestones for
 ### Noteworthy code-changes
   - On the GitHub Markdown reporter, checks which produce all the same output for a range of fonts are now automatically clustered into a family check result. (PR #3610)
 
+### Changes to existing checks
+#### On the Google Fonts Profile
+  - **[com.google.fonts/check/metadata/can_render_samples]:** Check that the fonts can render the sample texts for all languages specified on METADATA.pb, by using the new `gflanguages` module (issue #3605)
+
 
 ## 0.8.7 (2022-Feb-17)
 ### Noteworthy code-changes

Lib/fontbakery/profiles/googlefonts.py

@@ -5892,26 +5892,51 @@ def com_google_fonts_check_repo_sample_image(readme_contents, readme_directory,
         In order to prevent tofu from being seen on fonts.google.com, this check verifies that all samples provided on METADATA.pb can be properly rendered by the font.
     """,
     conditions = ["family_metadata"],
-    proposal = 'https://github.com/googlefonts/fontbakery/issues/3419',
+    proposal = ['https://github.com/googlefonts/fontbakery/issues/3419',
+                'https://github.com/googlefonts/fontbakery/issues/3605']
 )
 def com_google_fonts_check_metadata_can_render_samples(ttFont, family_metadata):
     """Check samples can be rendered."""
     from fontbakery.utils import can_shape
+    from gflanguages import lang_support
 
+    passed = True
     if not family_metadata.sample_glyphs:
-       yield SKIP,\
+       passed = False
+       yield INFO,\
              Message('no-samples',
                      'No sample_glyphs on METADATA.pb')
-       return
+    else:
+        for name, glyphs in family_metadata.sample_glyphs.items():
+            if not can_shape(ttFont, glyphs):
+                passed = False
+                yield FAIL,\
+                      Message('sample-glyphs',
+                              f"Font can't render the following sample glyphs:\n"
+                              f"'{name}': '{glyphs}'")
+
+    languages = lang_support.LoadLanguages()
+    for lang in family_metadata.languages:
+        # Note: checking agains all samples often results in
+        #       a way too verbose output. That's why I only left
+        #       the "tester" string for now.
+        SAMPLES = {
+            #'styles': languages[lang].sample_text.styles,
+            'tester': languages[lang].sample_text.tester,
+            #'specimen_16': languages[lang].sample_text.specimen_16,
+            #'specimen_21': languages[lang].sample_text.specimen_21,
+            #'specimen_32': languages[lang].sample_text.specimen_32,
+            #'specimen_36': languages[lang].sample_text.specimen_36,
+            #'specimen_48': languages[lang].sample_text.specimen_48
+        }
+        for sample_type, sample_text in SAMPLES.items():
+            if not can_shape(ttFont, sample_text):
+                passed = False
+                yield FAIL,\
+                      Message('sample-text',
+                              f'Font can\'t render "{lang}" sample text:\n'
+                              f'"{sample_text}"\n')
 
-    passed = True
-    for name, glyphs in family_metadata.sample_glyphs.items():
-        if not can_shape(ttFont, glyphs):
-            passed = False
-            yield FAIL,\
-                  Message('sample-glyphs',
-                          f"Font can't render the following sample glyphs:\n"
-                          f"'{name}': '{glyphs}'")
     if passed:
        yield PASS, "OK."
 

requirements.txt

@@ -7,6 +7,7 @@ defcon==0.10.0
 dehinter==4.0.0
 fontTools[ufo,lxml,unicode]==4.29.1
 font-v==2.1.0
+gflanguages==0.2.0
 glyphsets==0.2.1
 lxml==4.8.0
 opentype-sanitizer==8.2.1

setup.py

@@ -69,6 +69,7 @@
         'dehinter>=3.1.0', # 3.1.0 added dehinter.font.hint function
         'fontTools[ufo,lxml,unicode]>=3.34',  # 3.34 fixed some CFF2 issues, including calcBounds
         'font-v',
+        'gflanguages>=0.2.0', # 0.1.1 was under the GPLv3 (see: https://github.com/googlefonts/fontbakery/pull/3617#issuecomment-1044898812)
         'glyphsets',
         'lxml',
         'opentype-sanitizer>=7.1.9',  # 7.1.9 fixes caret value format = 3 bug

tests/profiles/googlefonts_test.py

@@ -4054,7 +4054,8 @@ def test_check_metadata_can_render_samples():
 
     # Cabin's METADATA.pb does not have sample_glyphs entry
     metadata_file = TEST_FILE("cabin/METADATA.pb")
-    assert_SKIP(check(metadata_file))
+    assert_results_contain(check(metadata_file),
+                           INFO, 'no-samples')
 
     # We add a small set of latin glyphs
     # that we're sure Cabin supports:
@@ -4068,8 +4069,6 @@ def test_check_metadata_can_render_samples():
                            FAIL, 'sample-glyphs')
 
     # TODO: expand the check to also validate sample_text fields
-    # TODO: maybe also fetch samples from the language textprotos
-    #       published on the google/fonts git repo
 
 
 def test_check_description_urls():