feat: add merge_prefs.py with full test coverage

scripts/merge_prefs.py

@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+"""
+merge_prefs.py — Merge Illuscape config patch into Inkscape preferences.xml
+
+Usage:
+    python3 merge_prefs.py --prefs ~/.config/inkscape/preferences.xml \
+                           --patch config/preferences-patch.xml \
+                           --preset cc|cs6
+"""
+import argparse
+import shutil
+from pathlib import Path
+from xml.etree import ElementTree as ET
+
+PRESET_OVERRIDES = {
+    "cc": {
+        ("options", "keyboard"): {"file": "illustrator-cc"},
+        ("options", "units"): {"doc": "px", "font": "px"},
+    },
+    "cs6": {
+        ("options", "keyboard"): {"file": "illustrator-cs6"},
+        ("options", "units"): {"doc": "pt", "font": "pt"},
+    },
+}
+
+
+def _find_or_create(parent: ET.Element, id_val: str) -> ET.Element:
+    """Return child with matching id, or create and append a new one."""
+    for child in parent:
+        if child.get("id") == id_val:
+            return child
+    child = ET.SubElement(parent, "group")
+    child.set("id", id_val)
+    return child
+
+
+def _merge_nodes(live_parent: ET.Element, patch_parent: ET.Element) -> None:
+    """Recursively upsert patch_parent's children into live_parent."""
+    for patch_child in patch_parent:
+        child_id = patch_child.get("id")
+        if child_id is None:
+            continue
+
+        live_child = _find_or_create(live_parent, child_id)
+
+        # Merge attributes: only set attrs present in patch; preserve unknown attrs
+        for attr, value in patch_child.attrib.items():
+            if attr != "id":
+                live_child.set(attr, value)
+
+        # Recurse into children
+        _merge_nodes(live_child, patch_child)
+
+
+def _apply_preset(root: ET.Element, preset: str) -> None:
+    """Apply preset-specific overrides (active keys file, document units)."""
+    for id_path, attrs in PRESET_OVERRIDES[preset].items():
+        node = root
+        for id_val in id_path:
+            node = _find_or_create(node, id_val)
+        for attr, value in attrs.items():
+            node.set(attr, value)
+
+
+def merge(prefs_path: Path, patch_path: Path, preset: str) -> None:
+    """Merge patch into prefs, applying preset overrides. Lenient: creates prefs if missing."""
+    patch_tree = ET.parse(patch_path)  # raises FileNotFoundError or ParseError
+    patch_root = patch_tree.getroot()
+
+    if not prefs_path.exists():
+        # Lenient: seed from patch, let Inkscape fill in the rest on first launch
+        prefs_path.parent.mkdir(parents=True, exist_ok=True)
+        shutil.copy(patch_path, prefs_path)
+        live_tree = ET.parse(prefs_path)
+        _apply_preset(live_tree.getroot(), preset)
+        live_tree.write(str(prefs_path), encoding="unicode", xml_declaration=True)
+        return
+
+    live_tree = ET.parse(prefs_path)  # raises ParseError on malformed XML
+    live_root = live_tree.getroot()
+
+    _merge_nodes(live_root, patch_root)
+    _apply_preset(live_root, preset)
+
+    live_tree.write(str(prefs_path), encoding="unicode", xml_declaration=True)
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Merge Illuscape preferences patch into Inkscape preferences.xml"
+    )
+    parser.add_argument("--prefs", required=True, type=Path)
+    parser.add_argument("--patch", required=True, type=Path)
+    parser.add_argument("--preset", required=True, choices=["cc", "cs6"])
+    args = parser.parse_args()
+
+    merge(args.prefs, args.patch, args.preset)
+    print(f"Illuscape preferences merged ({args.preset} preset)")
+
+
+if __name__ == "__main__":
+    main()

tests/test_merge_prefs.py

@@ -0,0 +1,140 @@
+"""Tests for scripts/merge_prefs.py"""
+import shutil
+import sys
+from pathlib import Path
+from xml.etree import ElementTree as ET
+
+import pytest
+
+sys.path.insert(0, str(Path(__file__).parent.parent / "scripts"))
+import merge_prefs
+
+FIXTURES = Path(__file__).parent / "fixtures"
+
+
+def _parse(path: Path) -> ET.Element:
+    return ET.parse(path).getroot()
+
+
+def _attr(root: ET.Element, *id_path: str) -> dict:
+    """Walk id_path through nested <group id=...> elements, return attribs."""
+    node = root
+    for id_val in id_path:
+        node = next(
+            (c for c in node if c.get("id") == id_val), None
+        )
+        assert node is not None, f"Node with id={id_val!r} not found"
+    return dict(node.attrib)
+
+
+# ── merge into existing prefs ─────────────────────────────────────────────────
+
+def test_merge_changes_patched_attributes(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-fresh.xml", prefs)
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    root = _parse(prefs)
+    assert _attr(root, "options", "scroll")["mousewheel-zoom"] == "false"
+    assert _attr(root, "options", "zoom")["mousewheel-zoom-ctrl"] == "true"
+    assert _attr(root, "tools", "nodes")["square-handles"] == "true"
+
+
+def test_merge_creates_missing_nodes(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-fresh.xml", prefs)
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    root = _parse(prefs)
+    assert _attr(root, "options", "new-group")["new-attr"] == "new-value"
+
+
+def test_merge_preserves_user_nodes(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-user-custom.xml", prefs)
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    root = _parse(prefs)
+    assert _attr(root, "options", "user-custom-setting")["my-value"] == "keep-this"
+    assert _attr(root, "tools", "user-tool-pref")["color"] == "#ff0000"
+
+
+def test_merge_preserves_existing_unknown_attributes(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-user-custom.xml", prefs)
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    root = _parse(prefs)
+    assert _attr(root, "tools", "nodes").get("user-pref") == "preserved"
+
+
+def test_merge_is_idempotent(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-fresh.xml", prefs)
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    content_after_first = prefs.read_text()
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    content_after_second = prefs.read_text()
+    assert content_after_first == content_after_second
+
+
+# ── lenient: no prefs file ────────────────────────────────────────────────────
+
+def test_merge_creates_prefs_when_missing(tmp_path):
+    prefs = tmp_path / "inkscape" / "preferences.xml"
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    assert prefs.exists()
+    root = _parse(prefs)
+    assert _attr(root, "options", "scroll")["mousewheel-zoom"] == "false"
+
+
+def test_merge_creates_parent_dirs_when_missing(tmp_path):
+    prefs = tmp_path / "deep" / "nested" / "dir" / "preferences.xml"
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    assert prefs.exists()
+
+
+# ── preset overrides ──────────────────────────────────────────────────────────
+
+def test_preset_cc_sets_keys_file(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-fresh.xml", prefs)
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    root = _parse(prefs)
+    assert _attr(root, "options", "keyboard")["file"] == "illustrator-cc"
+
+
+def test_preset_cs6_sets_keys_file(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-fresh.xml", prefs)
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cs6")
+    root = _parse(prefs)
+    assert _attr(root, "options", "keyboard")["file"] == "illustrator-cs6"
+
+
+def test_preset_cc_sets_px_units(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-fresh.xml", prefs)
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+    root = _parse(prefs)
+    assert _attr(root, "options", "units")["doc"] == "px"
+
+
+def test_preset_cs6_sets_pt_units(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-fresh.xml", prefs)
+    merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cs6")
+    root = _parse(prefs)
+    assert _attr(root, "options", "units")["doc"] == "pt"
+
+
+# ── error handling ────────────────────────────────────────────────────────────
+
+def test_merge_raises_on_malformed_prefs(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    prefs.write_text("this is not xml")
+    with pytest.raises(ET.ParseError):
+        merge_prefs.merge(prefs, FIXTURES / "patch-minimal.xml", "cc")
+
+
+def test_merge_raises_on_missing_patch(tmp_path):
+    prefs = tmp_path / "preferences.xml"
+    shutil.copy(FIXTURES / "prefs-fresh.xml", prefs)
+    with pytest.raises(FileNotFoundError):
+        merge_prefs.merge(prefs, tmp_path / "nonexistent-patch.xml", "cc")