From a79106d09ab8ad29cbff1ed93058e5ac755cc1f5 Mon Sep 17 00:00:00 2001
From: Cosimo Lupo <clupo@google.com>
Date: Fri, 12 Nov 2021 18:59:09 +0000
Subject: [PATCH] add simple subset/svg_test.py

---
 Tests/subset/subset_test.py |  13 +++++
 Tests/subset/svg_test.py    | 113 ++++++++++++++++++++++++++++++++++++
 2 files changed, 126 insertions(+)
 create mode 100644 Tests/subset/svg_test.py

diff --git a/Tests/subset/subset_test.py b/Tests/subset/subset_test.py
index aeb4ce1d9..d8f4dac0c 100644
--- a/Tests/subset/subset_test.py
+++ b/Tests/subset/subset_test.py
@@ -7,6 +7,7 @@ from fontTools.pens.ttGlyphPen import TTGlyphPen
 from fontTools.ttLib import TTFont, newTable
 from fontTools.ttLib.tables import otTables as ot
 from fontTools.misc.loggingTools import CapturingLogHandler
+from fontTools.subset.svg import etree
 import difflib
 import logging
 import os
@@ -1339,5 +1340,17 @@ def test_subset_keep_size_drop_empty_stylistic_set():
     assert font["GSUB"].table.FeatureList.FeatureCount == 0
 
 
+@pytest.mark.skipif(etree is not None, reason="lxml is installed")
+def test_subset_svg_missing_lxml(ttf_path):
+    # add dummy SVG table and confirm we raise ImportError upon trying to subset it
+    font = TTFont(ttf_path)
+    font["SVG "] = newTable("SVG ")
+    font["SVG "].docList = [('<svg><g id="glyph1"/></svg>', 1, 1)]
+    font.save(ttf_path)
+
+    with pytest.raises(ModuleNotFoundError):
+        subset.main([str(ttf_path), "--gids=0,1"])
+
+
 if __name__ == "__main__":
     sys.exit(unittest.main())
diff --git a/Tests/subset/svg_test.py b/Tests/subset/svg_test.py
new file mode 100644
index 000000000..acaeb57db
--- /dev/null
+++ b/Tests/subset/svg_test.py
@@ -0,0 +1,113 @@
+from string import ascii_letters
+
+from fontTools.misc.testTools import getXML
+from fontTools import subset
+from fontTools.fontBuilder import FontBuilder
+from fontTools.pens.ttGlyphPen import TTGlyphPen
+from fontTools.ttLib import TTFont, newTable
+from fontTools.subset.svg import NAMESPACES
+
+import pytest
+
+etree = pytest.importorskip("lxml.etree")
+
+
+@pytest.fixture
+def empty_svg_font():
+    glyph_order = [".notdef"] + list(ascii_letters)
+
+    pen = TTGlyphPen(glyphSet=None)
+    pen.moveTo((0, 0))
+    pen.lineTo((0, 500))
+    pen.lineTo((500, 500))
+    pen.lineTo((500, 0))
+    pen.closePath()
+    glyph = pen.glyph()
+    glyphs = {g: glyph for g in glyph_order}
+
+    fb = FontBuilder(unitsPerEm=1024, isTTF=True)
+    fb.setupGlyphOrder(glyph_order)
+    fb.setupCharacterMap({ord(c): c for c in ascii_letters})
+    fb.setupGlyf(glyphs)
+    fb.setupHorizontalMetrics({g: (500, 0) for g in glyph_order})
+    fb.setupHorizontalHeader()
+    fb.setupOS2()
+    fb.setupPost()
+    fb.setupNameTable({"familyName": "TestSVG", "styleName": "Regular"})
+
+    svg_table = newTable("SVG ")
+    svg_table.docList = []
+    fb.font["SVG "] = svg_table
+
+    return fb.font
+
+
+def new_svg(**attrs):
+    return etree.Element("svg", {"xmlns": NAMESPACES["svg"], **attrs})
+
+
+def test_subset_svg_simple(empty_svg_font, tmp_path):
+    # 'simple' as in one glyph per svg doc
+    font = empty_svg_font
+
+    svg_docs = font["SVG "].docList
+    for i in range(1, 11):
+        svg = new_svg()
+        etree.SubElement(svg, "path", {"id": f"glyph{i}", "d": f"M{i},{i}"})
+        svg_docs.append((etree.tostring(svg).decode(), i, i))
+
+    svg_font_path = tmp_path / "TestSVG.ttf"
+    font.save(svg_font_path)
+
+    subset_path = svg_font_path.with_suffix(".subset.ttf")
+
+    # keep four glyphs in total, don't retain gids, which thus get remapped
+    subset.main(
+        [
+            str(svg_font_path),
+            f"--output-file={subset_path}",
+            "--gids=2,4-6",
+        ]
+    )
+    subset_font = TTFont(subset_path)
+
+    assert getXML(subset_font["SVG "].toXML, subset_font) == [
+        '<svgDoc endGlyphID="1" startGlyphID="1">',
+        '  <![CDATA[<svg xmlns="http://www.w3.org/2000/svg"><path id="glyph1" d="M2,2"/></svg>]]>',
+        "</svgDoc>",
+        '<svgDoc endGlyphID="2" startGlyphID="2">',
+        '  <![CDATA[<svg xmlns="http://www.w3.org/2000/svg"><path id="glyph2" d="M4,4"/></svg>]]>',
+        "</svgDoc>",
+        '<svgDoc endGlyphID="3" startGlyphID="3">',
+        '  <![CDATA[<svg xmlns="http://www.w3.org/2000/svg"><path id="glyph3" d="M5,5"/></svg>]]>',
+        "</svgDoc>",
+        '<svgDoc endGlyphID="4" startGlyphID="4">',
+        '  <![CDATA[<svg xmlns="http://www.w3.org/2000/svg"><path id="glyph4" d="M6,6"/></svg>]]>',
+        "</svgDoc>",
+    ]
+
+    # same four glyphs, now retain gids
+    subset.main(
+        [
+            str(svg_font_path),
+            f"--output-file={subset_path}",
+            "--gids=2,4-6",
+            "--retain-gids",
+        ]
+    )
+    subset_font = TTFont(subset_path)
+
+    assert getXML(subset_font["SVG "].toXML, subset_font) == [
+        '<svgDoc endGlyphID="2" startGlyphID="2">',
+        '  <![CDATA[<svg xmlns="http://www.w3.org/2000/svg"><path id="glyph2" d="M2,2"/></svg>]]>',
+        "</svgDoc>",
+        '<svgDoc endGlyphID="4" startGlyphID="4">',
+        '  <![CDATA[<svg xmlns="http://www.w3.org/2000/svg"><path id="glyph4" d="M4,4"/></svg>]]>',
+        "</svgDoc>",
+        '<svgDoc endGlyphID="5" startGlyphID="5">',
+        '  <![CDATA[<svg xmlns="http://www.w3.org/2000/svg"><path id="glyph5" d="M5,5"/></svg>]]>',
+        "</svgDoc>",
+        '<svgDoc endGlyphID="6" startGlyphID="6">',
+        '  <![CDATA[<svg xmlns="http://www.w3.org/2000/svg"><path id="glyph6" d="M6,6"/></svg>]]>',
+        "</svgDoc>",
+    ]