Migrate LESS to nested CSS

.github/workflows/ci.yml

@@ -53,7 +53,7 @@ jobs:
     - name: apt install
       run: |
         sudo apt-get update
-        sudo apt-get install --no-install-suggests --no-install-recommends inkscape icoutils scour optipng node-less node-source-map
+        sudo apt-get install --no-install-suggests --no-install-recommends inkscape icoutils scour optipng
 
     - uses: actions/[email protected]
       with:

README.md

@@ -25,8 +25,7 @@ The [conventions document](./conventions.md) describes some idioms used in the c
 Grab the build dependencies with:
 
     $ sudo apt install brotli inkscape icoutils git scour optipng \
-                       python3-dev build-essential \
-                       node-less node-source-map
+                       python3-dev build-essential
 
 [Install pip](https://pip.pypa.io/en/latest/installing/#get-pip), then install [Tox](http://tox.readthedocs.org/en/latest/).
 (I actually recommend installing this in your home directory, but that's outside the scope of this document.)

bin/compile-static.py

@@ -1,5 +1,5 @@
 #!/usr/bin/python3
-# Copyright © 2018, 2019, 2020, 2022 Tom Most <[email protected]>
+# Copyright © 2018, 2019, 2020, 2022, 2024 Tom Most <[email protected]>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -49,13 +49,16 @@
 import re
 import shlex
 from asyncio.subprocess import PIPE
-from dataclasses import dataclass
+from collections import deque
+from dataclasses import dataclass, field
 from pathlib import Path
 from shutil import rmtree
 from typing import Optional, Sequence
 
 import brotli
+import tinycss2
 import zopfli.gzip
+from tinycss2.ast import AtRule, ParseError
 
 repo_root = Path(__file__).parent.parent
 
@@ -244,39 +247,57 @@ async def process_svg(svg: Path, w: Writer) -> None:
     w.add_file_bytes(hashname(svg.stem, "svg", svg_bytes), svg_bytes)
 
 
-async def process_less(less: Path, build_dir: Path, w: Writer) -> None:
+async def process_css(css: Path, w: Writer) -> None:
     """
-    Convert .less to a CSS file and source map.
+    Process a stylesheet to inline stylesheets referenced via @include rules.
     """
-    css_path = build_dir / f"{less.stem}.css"
-    map_path = build_dir / f"{less.stem}.css.map"
-    await _run(
-        [
-            "/usr/bin/node",
-            "/usr/bin/lessc",
-            "--no-js",
-            "--strict-imports",
-            f"--source-map={map_path}",
-            str(less),
-            str(css_path),
-        ]
-    )
-    css = css_path.read_bytes()
-    css_name = hashname(less.stem, "css", css)
-    map_name = f"{css_name}.map"
+    combiner = CombinedCss(root_dir=css.parent)
+    combiner.include(css.name, "utf-8")
+
+    combined = combiner.serialize().encode("utf-8")
+    w.add_file_bytes(hashname(css.stem, "css", combined), combined)
+
 
-    # We must change the source map reference on the last line when renaming
-    # the file.
-    last_line_index = css.rindex(b"\n") + 1
-    last_line = css[last_line_index:]
-    if not last_line.startswith(b"/*# sourceMappingURL="):
-        raise Exception("Expected sourceMappingURL comment at the end of {css_path}, but found {last_line!r}")
+@dataclass
+class CombinedCss:
+    root_dir: Path
+    _included: set[str] = field(default_factory=set, init=False)
+    _rules: list[object] = field(default_factory=list, init=False)
+
+    def include(self, path: str, protocol_encoding=None, environment_encoding=None) -> None:
+        if path in self._included:
+            # print(f"Skipping duplicate @import {path!r}")
+            return
+        else:
+            # TODO: Should normalize the path to avoid dupe includes
+            # TODO: Should verify the path is within root_dir
+            # print(f"Including rules from @import {path!r}")
+            self._included.add(path)
+
+        with (self.root_dir / path).open("rb") as f:
+            rules, encoding = tinycss2.parse_stylesheet_bytes(
+                f.read(),
+                protocol_encoding,
+                environment_encoding,
+            )
 
-    # ❤ copies
-    css = css[:last_line_index] + f"/*# sourceMappingURL={map_name} */".encode()
+        for rule in rules:
+            if rule.type == "at-rule" and rule.lower_at_keyword == "import":
+                # We only support the form `@import "./foo". The full syntax is quite complex:
+                # https://developer.mozilla.org/en-US/docs/Web/CSS/@import
+                [ws, urlish] = rule.prelude
+                assert ws.type == "whitespace"
+                assert urlish.type == "string"
+                self.include(urlish.value)
+            elif rule.type == "parse-error":
+                # Note that very little counts as a parse error in CSS, so
+                # this is not a useful diagnostic tool.
+                raise ValueError(f"Parse error in {path}: {rule.message}")
+            else:
+                self._rules.append(rule)
 
-    w.add_file_bytes(css_name, css)
-    w.add_file(map_name, map_path)
+    def serialize(self):
+        return tinycss2.serialize(self._rules)
 
 
 async def process_glob(paths: Path, w: Writer) -> None:
@@ -347,7 +368,7 @@ async def _main(build_dir: Path, out_dir: Path, compress: bool) -> None:
         process_svg(repo_root / "img" / "lettertype.svg", w),
         process_svg(repo_root / "img" / "logotype.svg", w),
         process_glob((repo_root / "vendor" / "normalize.css").glob("normalize-*.css"), w),
-        process_less(repo_root / "less" / "main.less", build_dir, w),
+        process_css(repo_root / "css" / "main.css", w),
         process_fonts(repo_root, w),
     )
     print(w.summarize())

less/Article.less → css/Article.css

@@ -1,6 +1,3 @@
-@import "./include.less";
-
-
 .article-header {
     display: grid;
     grid-template-columns: 1fr min-content;
@@ -17,6 +14,7 @@
     .tools {
         display: flex;
         flex-flow: row nowrap;
+        --focus-offset: var(--focus-offset-in); /* Don't clip focus ring. */
 
         .icon {
             width: 2em;

less/FeedView.less → css/FeedView.css

@@ -1,5 +1,3 @@
-@import "./include.less";
-
 .feed-header {
     h1 {
         margin: 1rem 0;

less/GlobalBar.less → css/GlobalBar.css

@@ -1,5 +1,3 @@
-@import "./include.less";
-
 .yarrharr-masthead {
     display: flex;
     flex: 0 0 auto;
@@ -36,8 +34,6 @@
     display: flex;
     align-items: center;
     justify-content: center;
-
-    .flat-button;
-
+    --focus-offset: var(--focus-offset-in); /* Don't clip focus ring. */
     padding: 1rem; /* Ensure spacing between */
 }

less/ListArticle.less → css/ListArticle.css

@@ -1,11 +1,8 @@
-@import "./include.less";
-
 .list-article {
     margin: 0.75rem 0;
 }
 
 .list-article-inner {
-    // max-width: var(--layout-max-width);
     margin: 0 auto;
     overflow: hidden;
 }
@@ -14,14 +11,14 @@
     display: flex;
     flex-flow: row nowrap;
     align-items: stretch;
+    --focus-offset: var(--focus-offset-in); /* Don't clip focus ring. */
 
     .outbound {
-        .flat-button;
-        padding: ((2 * @button_border_width));
+        padding: calc(2 * var(--button-border-width));
         flex: 1 1 100%;
         width: 100%;
         display: grid;
-        // XXX: Using grid here is starting to look a little silly.
+        /* XXX: Using grid here is starting to look a little silly. */
         grid-template-areas:
             "meta1"
             "meta2";
@@ -37,12 +34,10 @@
             color: var(--quiet-text-color);
             text-transform: uppercase;
             font-size: smaller;
-            // background: red;
         }
         .meta2 {
             grid-area: meta2;
             font-family: "Newsreader";
-            // background: blue;
         }
         .meta1,
         .meta2 {
@@ -61,33 +56,28 @@
 
     read-toggle,
     .view-link {
-        flex: 0 0 @bar_height;
+        flex: 0 0 var(--bar-height);
     }
     read-toggle {
         button {
-            .flat-button;
             width: 100%;
             height: 100%;
         }
-        // background: purple;
     }
     .view-link {
-        // background: magenta;
-        .flat-button;
     }
 
     .outbound-icon,
     read-toggle button,
     .view-link {
-        font-size: @icon_size;
+        font-size: var(--icon-size);
         display: flex;
         flex-flow: row nowrap;
         align-items: center;
         justify-content: center;
 
         .icon {
             flex: 0 0 auto;
-            // background: white;
             display: block;
             align-self: center;
             justify-self: center;

less/StateToggle.less → css/StateToggle.css

@@ -1,7 +1,7 @@
 fave-toggle {
     button {
-        .flat-button;
-        padding: 1px 4px;
+        background: transparent;
+        border: none;
     }
 
     .inactive {
@@ -22,8 +22,8 @@ fave-toggle {
 
 read-toggle {
     button {
-        .flat-button;
-        padding: 1px 4px;
+        background: transparent;
+        border: none;
     }
 
     .inactive {

less/Tabs.less → css/Tabs.css

@@ -1,5 +1,3 @@
-@import "./include.less";
-
 /**
  * <div.tabs>
  *   <div.tabs-tabs>
@@ -29,7 +27,7 @@
     border-radius: 4px 4px 0 0;
     text-decoration: none;
     line-height: 1.7;
-    padding: 0.125rem 8px 0 8px;
+    padding: 0.125rem 8px 2px 8px;
     white-space: nowrap;
     text-align: center;
     text-overflow: ellipsis;