Rewrite ElideText unittests

This CL is rewriting the ElideText unittests.
The goal of this rewrite is to allow adding more unittests.
  * ELIDE_HEAD
  * ELIDE_EMAIL
  * ELIDE_MIDDLE
  * Eliding with styles

It is now using a templated tests to ease debugging.

A change to the way glyph_width_for_test_ work was needed.
Zero width codepoints will stay zero width, even if a
glyph width is provided. This is required to ensures
RLM and LRM (directional marker) stay with width zero.
Otherwise a DCHECK is failing since the text can be larger
with eliding (2 glyphs instead of 1 glyph).

Bug: 1025561
Change-Id: I19f18fb99f52edbbb59d170f7b47bef3a3f3de5f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1975056
Commit-Queue: Etienne Bergeron <etienneb@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726406}

ui/gfx/render_text_harfbuzz.cc

@@ -1337,10 +1337,13 @@ void ShapeRunWithFont(const ShapeRunWithFontInput& in,
     const SkScalar y_offset =
         HarfBuzzUnitsToSkiaScalar(hb_positions[i].y_offset);
     out->positions[i].set(out->width + x_offset, -y_offset);
-    out->width += (in.glyph_width_for_test > 0)
-                      ? in.glyph_width_for_test
-                      : HarfBuzzUnitsToFloat(hb_positions[i].x_advance) +
-                            in.glyph_spacing;
+
+    if (in.glyph_width_for_test == 0)
+      out->width +=
+          HarfBuzzUnitsToFloat(hb_positions[i].x_advance) + in.glyph_spacing;
+    else if (hb_positions[i].x_advance)  // Leave zero-width glyphs alone.
+      out->width += in.glyph_width_for_test;
+
     // Round run widths if subpixel positioning is off to match native behavior.
     if (!in.render_params.subpixel_positioning)
       out->width = std::round(out->width);

ui/gfx/render_text_unittest.cc

@@ -1751,92 +1751,109 @@ INSTANTIATE_TEST_SUITE_P(ItemizeTextToRunsEmoji,
                          ::testing::ValuesIn(kEmojiRunListCases),
                          RenderTextTestWithRunListCase::ParamInfoToString);
 
-TEST_F(RenderTextTest, ElidedText) {
-  // TODO(skanuj) : Add more test cases for following
-  // - RenderText styles.
-  // - Cross interaction of truncate, elide and obscure.
-  // - ElideText tests from text_elider.cc.
-  struct {
+struct ElideTextCase {
+  const char* test_name;
   const wchar_t* text;
   const wchar_t* display_text;
-    const bool elision_expected;
-  } cases[] = {
-      // Strings shorter than the elision width should be laid out in full.
-      {L"", L"", false},
-      {L"M", L"", false},
-      {L" . ", L" . ", false},  // a wide kWeak
-      {L"abc", L"abc", false},  // a wide kLtr
-      {L"\u05d0\u05d1\u05d2", L"\u05d0\u05d1\u05d2", false},  // a wide kRtl
-      {L"a\u05d0\u05d1", L"a\u05d0\u05d1", false},  // a wide kLtrRtl
-      {L"a\u05d1b", L"a\u05d1b", false},  // a wide kLtrRtlLtr
-      {L"\u05d0\u05d1a", L"\u05d0\u05d1a", false},  // a wide kRtlLtr
-      {L"\u05d0a\u05d1", L"\u05d0a\u05d1", false},  // a wide kRtlLtrRtl
-      // Strings as long as the elision width should be laid out in full.
-      {L"012ab", L"012ab", false},
-      // Long strings should be elided with an ellipsis appended at the end.
-      {L"012abc", L"012a\u2026", true},
-      {L"012ab\u05d0\u05d1", L"012a\u2026", true},
-      {L"012a\u05d1b", L"012a\u2026", true},
+};
+
+class RenderTextTestWithElideTextCase
+    : public RenderTextTest,
+      public ::testing::WithParamInterface<ElideTextCase> {
+ public:
+  static std::string ParamInfoToString(
+      ::testing::TestParamInfo<ElideTextCase> param_info) {
+    return param_info.param.test_name;
+  }
+};
+
+TEST_P(RenderTextTestWithElideTextCase, ElideText) {
+  // This test requires glyphs to be the same width.
+  constexpr int kGlyphWidth = 10;
+  SetGlyphWidth(kGlyphWidth);
+
+  ElideTextCase param = GetParam();
+  const base::string16 text = WideToUTF16(param.text);
+  const base::string16 display_text = WideToUTF16(param.display_text);
+
+  // Retrieve the display_text width without eliding.
+  RenderTextHarfBuzz* render_text = GetRenderText();
+  render_text->SetText(display_text);
+  const int expected_width = render_text->GetContentWidth();
+
+  // Set the text and the eliding behavior.
+  render_text->SetText(text);
+  render_text->SetDisplayRect(
+      Rect(0, 0, expected_width + kGlyphWidth / 2, 100));
+  render_text->SetElideBehavior(ELIDE_TAIL);
+  render_text->SetWhitespaceElision(false);
+  const int elided_width = render_text->GetContentWidth();
+
+  EXPECT_EQ(text, render_text->text());
+  EXPECT_EQ(display_text, render_text->GetDisplayText());
+  EXPECT_EQ(elided_width, expected_width);
+}
+
+const ElideTextCase kElideTailTextCases[] = {
+    {"empty", L"", L""},
+    {"letter_m_tail0", L"M", L""},
+    {"letter_m_tail1", L"M", L"M"},
+    {"letter_weak_3", L" . ", L" . "},
+    {"letter_weak_2", L" . ", L" \u2026"},
+    {"no_eliding", L"012ab", L"012ab"},
+    {"ltr_3", L"abc", L"abc"},
+    {"ltr_2", L"abc", L"a\u2026"},
+    {"ltr_1", L"abc", L"\u2026"},
+    {"ltr_0", L"abc", L""},
+    {"rtl_3", L"\u05d0\u05d1\u05d2", L"\u05d0\u05d1\u05d2"},
+    {"rtl_2", L"\u05d0\u05d1\u05d2", L"\u05d0\u2026"},
+    {"rtl_1", L"\u05d0\u05d1\u05d2", L"\u2026\x200E"},
+    {"rtl_0", L"\u05d0\u05d1\u05d2", L""},
+    {"ltr_rtl_5", L"abc\u05d0\u05d1\u05d2", L"abc\u05d0\u2026\x200F"},
+    {"ltr_rtl_4", L"abc\u05d0\u05d1\u05d2", L"abc\u2026"},
+    {"ltr_rtl_3", L"abc\u05d0\u05d1\u05d2", L"ab\u2026"},
+    {"rtl_ltr_5", L"\u05d0\u05d1\u05d2abc", L"\u05d0\u05d1\u05d2a\u2026\x200E"},
+    {"rtl_ltr_4", L"\u05d0\u05d1\u05d2abc", L"\u05d0\u05d1\u05d2\u2026"},
+    {"rtl_ltr_3", L"\u05d0\u05d1\u05d2abc", L"\u05d0\u05d1\u2026"},
+    {"bidi_1", L"012a\u05d1b\u05d1c", L"012a\u2026"},
+    {"bidi_2", L"012a\u05d1b\u05d1c", L"012a\u05d1\u2026\x200F"},
+    {"bidi_3", L"012a\u05d1b\u05d1c", L"012a\u05d1b\u2026\x200F"},
     // No RLM marker added as digits (012) have weak directionality.
-      {L"01\u05d0\u05d1\u05d2", L"01\u05d0\u05d1\u2026", true},
+    {"no_rlm", L"01\u05d0\u05d1\u05d2", L"01\u05d0\u2026"},
     // RLM marker added as "ab" have strong LTR directionality.
-      {L"ab\u05d0\u05d1\u05d2", L"ab\u05d0\u05d1\u2026\u200f", true},
+    {"with_rlm", L"ab\u05d0\u05d1\u05d2cd", L"ab\u05d0\u05d1\u2026\u200f"},
     // Test surrogate pairs. The first pair 𝄞 'MUSICAL SYMBOL G CLEF' U+1D11E
     // should be kept, and the second pair 𝄢 'MUSICAL SYMBOL F CLEF' U+1D122
     // should be removed. No surrogate pair should be partially elided.
-      // Windows requires wide strings for \Unnnnnnnn universal character names.
-      {L"0123\U0001D11E\U0001D122", L"0123\U0001D11E\u2026", true},
+    {"surrogate", L"0123\U0001D11E\U0001D122x", L"0123\U0001D11E\u2026"},
     // Test combining character sequences. U+0915 U+093F forms a compound
     // glyph, as does U+0915 U+0942. The first should be kept; the second
     // removed. No combining sequence should be partially elided.
-      {L"0123\u0915\u093f\u0915\u0942", L"0123\u0915\u093f\u2026", true},
+    {"combining", L"0123\u0915\u093f\u0915\u0942456",
+     L"0123\u0915\u093f\u2026"},
     // U+05E9 U+05BC U+05C1 U+05B8 forms a four-character compound glyph.
     // It should be either fully elided, or not elided at all. If completely
     // elided, an LTR Mark (U+200E) should be added.
-      {L"0\u05e9\u05bc\u05c1\u05b8", L"0\u05e9\u05bc\u05c1\u05b8", false},
-      {L"0\u05e9\u05bc\u05c1\u05b8", L"0\u2026\u200E", true},
-      {L"01\u05e9\u05bc\u05c1\u05b8", L"01\u2026\u200E", true},
-      {L"012\u05e9\u05bc\u05c1\u05b8", L"012\u2026\u200E", true},
+    {"grapheme1", L"0\u05e9\u05bc\u05c1\u05b8", L"0\u05e9\u05bc\u05c1\u05b8"},
+    {"grapheme2", L"0\u05e9\u05bc\u05c1\u05b8abc", L"0\u2026\u200E"},
+    {"grapheme3", L"01\u05e9\u05bc\u05c1\u05b8abc", L"01\u2026\u200E"},
+    {"grapheme4", L"012\u05e9\u05bc\u05c1\u05b8abc", L"012\u2026\u200E"},
     // 𝄞 (U+1D11E, MUSICAL SYMBOL G CLEF) should be fully elided.
-      // Windows requires wide strings for \Unnnnnnnn universal character names.
-      {L"012\U0001D11E", L"012\u2026", true},
-  };
-
-  auto expected_render_text = std::make_unique<RenderTextHarfBuzz>();
-  expected_render_text->SetFontList(FontList("serif, Sans serif, 12px"));
-  expected_render_text->SetDisplayRect(Rect(0, 0, 9999, 100));
+    {"emoji", L"012\U0001D11Ex", L"012\u2026"},
+};
 
-  RenderText* render_text = GetRenderText();
-  render_text->SetFontList(FontList("serif, Sans serif, 12px"));
-  render_text->SetElideBehavior(ELIDE_TAIL);
-
-  for (size_t i = 0; i < base::size(cases); i++) {
-    SCOPED_TRACE(base::StringPrintf("Testing cases[%" PRIuS "] '%ls'", i,
-                                    cases[i].text));
-
-    // Compute expected width
-    expected_render_text->SetText(WideToUTF16(cases[i].display_text));
-    int expected_width = expected_render_text->GetContentWidth();
-
-    base::string16 input = WideToUTF16(cases[i].text);
-    // Extend the input text to ensure that it is wider than the display_text,
-    // and so it will get elided.
-    if (cases[i].elision_expected)
-      input.append(UTF8ToUTF16(" MMMMMMMMMMM"));
-    render_text->SetText(input);
-    render_text->SetDisplayRect(Rect(0, 0, expected_width, 100));
-    EXPECT_EQ(input, render_text->text());
-    EXPECT_EQ(WideToUTF16(cases[i].display_text),
-              render_text->GetDisplayText());
-    expected_render_text->SetText(base::string16());
-  }
-}
+INSTANTIATE_TEST_SUITE_P(ElideTail,
+                         RenderTextTestWithElideTextCase,
+                         ::testing::ValuesIn(kElideTailTextCases),
+                         RenderTextTestWithElideTextCase::ParamInfoToString);
 
 TEST_F(RenderTextTest, ElidedText_NoTrimWhitespace) {
-  const int kGlyphWidth = 10;
+  // This test requires glyphs to be the same width.
+  constexpr int kGlyphWidth = 10;
+  SetGlyphWidth(kGlyphWidth);
+
   RenderText* render_text = GetRenderText();
   gfx::test::RenderTextTestApi render_text_test_api(render_text);
-  render_text_test_api.SetGlyphWidth(kGlyphWidth);
   render_text->SetElideBehavior(ELIDE_TAIL);
   render_text->SetWhitespaceElision(false);
 
@@ -1867,7 +1884,6 @@ TEST_F(RenderTextTest, ElidedText_NoTrimWhitespace) {
 
 TEST_F(RenderTextTest, ElidedObscuredText) {
   auto expected_render_text = std::make_unique<RenderTextHarfBuzz>();
-  expected_render_text->SetFontList(FontList("serif, Sans serif, 12px"));
   expected_render_text->SetDisplayRect(Rect(0, 0, 9999, 100));
   const base::char16 elided_obscured_text[] = {
       RenderText::kPasswordReplacementChar,
@@ -1875,7 +1891,6 @@ TEST_F(RenderTextTest, ElidedObscuredText) {
   expected_render_text->SetText(elided_obscured_text);
 
   RenderText* render_text = GetRenderText();
-  render_text->SetFontList(FontList("serif, Sans serif, 12px"));
   render_text->SetElideBehavior(ELIDE_TAIL);
   render_text->SetDisplayRect(
       Rect(0, 0, expected_render_text->GetContentWidth(), 100));
@@ -2151,7 +2166,7 @@ TEST_F(RenderTextTest, ElidedStyledTextRtl) {
         break;
     }
   }
-}  // namespace gfx
+}
 
 TEST_F(RenderTextTest, ElidedEmail) {
   RenderText* render_text = GetRenderText();