From 2abce81246e9cc2d034b4cca04e58b0b7a416cab Mon Sep 17 00:00:00 2001
From: juprodh <juprodh@proton.me>
Date: Fri, 21 Aug 2026 12:29:31 +0800
Subject: [PATCH] Size images from a digits-only alt

Signed-off-by: juprodh <juprodh@proton.me>
---
 README.md                        |  2 +-
 src/lib/markdown/image-plugin.ts | 40 +++++++++++++++++++++-----------
 tests/lib/markdown.test.ts       | 19 +++++++++++++++
 3 files changed, 46 insertions(+), 15 deletions(-)

diff --git a/README.md b/README.md
index 2370ec6..a506f19 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,7 @@ imports here; see [Bases and Canvas](#bases-and-canvas) below.
 | YouTube embed `![](url)` | ✅ | ✅ | — |
 | Tweet embed `![](url)` | — plain link, by design | ✅ | — |
 | Image sizing `![alt\|300](…)` | ✅ | ✅ | — |
-| Image sizing, no alt `![300](…)` | — | ✅ | — |
+| Image sizing, no alt `![300](…)` | ✅ | ✅ | — |
 | PDF / audio embeds `![[file.pdf]]` | — | ✅ | — |
 | Transclusion `![[note]]` | — | ✅ | — |
 | Block references `[[note#^id]]` | ✅ ids you type | ✅ auto-minted too | — |
diff --git a/src/lib/markdown/image-plugin.ts b/src/lib/markdown/image-plugin.ts
index 19b122a..0976cc4 100644
--- a/src/lib/markdown/image-plugin.ts
+++ b/src/lib/markdown/image-plugin.ts
@@ -1,24 +1,36 @@
 import type { MarkdownIt, Token } from "markdown-it";
 
-const SIZE_RE = /\|(\d+)(?:x(\d+))?$/;
+const SUFFIX_SIZE_RE = /\|(\d+)(?:x(\d+))?$/;
+const BARE_SIZE_RE = /^(\d+)(?:x(\d+))?$/;
 
-// Obsidian sizes an image with `![alt|300](…)` or `![alt|300x200](…)`. The alt is built
-// from the token's children, so the suffix has to come off there too — otherwise a
-// screen reader announces the number as part of the description.
+function applySize(token: Token, width: string, height?: string): void {
+	if (token.attrIndex("width") < 0) token.attrPush(["width", width]);
+	if (height && token.attrIndex("height") < 0)
+		token.attrPush(["height", height]);
+}
+
+// Obsidian sizes an image with `![alt|300](…)`, `![alt|300x200](…)`, or — when there is no
+// alt to hang the suffix on — a wholly numeric alt, `![300](…)`. Either way the number is a
+// dimension, not a description: the alt is built from the token's children, so it has to
+// come off there too, or a screen reader announces the number as the image.
 function applySizeFromAlt(token: Token): void {
-	const match = SIZE_RE.exec(token.content);
+	const bare = BARE_SIZE_RE.exec(token.content);
+	if (bare) {
+		token.children = [];
+		token.content = "";
+		applySize(token, bare[1] as string, bare[2]);
+		return;
+	}
+
+	const match = SUFFIX_SIZE_RE.exec(token.content);
 	if (!match) return;
 
 	const last = token.children?.at(-1);
-	if (last?.type !== "text" || !SIZE_RE.test(last.content)) return;
-
-	last.content = last.content.replace(SIZE_RE, "");
-	token.content = token.content.replace(SIZE_RE, "");
-	if (token.attrIndex("width") < 0)
-		token.attrPush(["width", match[1] as string]);
-	if (match[2] && token.attrIndex("height") < 0) {
-		token.attrPush(["height", match[2]]);
-	}
+	if (last?.type !== "text" || !SUFFIX_SIZE_RE.test(last.content)) return;
+
+	last.content = last.content.replace(SUFFIX_SIZE_RE, "");
+	token.content = token.content.replace(SUFFIX_SIZE_RE, "");
+	applySize(token, match[1] as string, match[2]);
 }
 
 // Content images (`![](…)`) render eager by default, so a note with many embedded
diff --git a/tests/lib/markdown.test.ts b/tests/lib/markdown.test.ts
index d7d1537..5a62fb5 100644
--- a/tests/lib/markdown.test.ts
+++ b/tests/lib/markdown.test.ts
@@ -45,6 +45,25 @@ describe("renderMarkdown", () => {
 		expect(html).toContain('alt="diagram"');
 	});
 
+	test("reads an Obsidian width off a wholly numeric alt", () => {
+		const { html } = renderMarkdown("![300](https://example.com/x.png)");
+		expect(html).toContain('width="300"');
+		expect(html).toContain('alt=""');
+	});
+
+	test("reads width and height off a wholly numeric alt", () => {
+		const { html } = renderMarkdown("![300x200](https://example.com/x.png)");
+		expect(html).toContain('width="300"');
+		expect(html).toContain('height="200"');
+		expect(html).toContain('alt=""');
+	});
+
+	test("leaves an alt that only starts with digits alone", () => {
+		const { html } = renderMarkdown("![300 dpi](https://example.com/x.png)");
+		expect(html).toContain('alt="300 dpi"');
+		expect(html).not.toContain("width=");
+	});
+
 	test("leaves a non-numeric pipe in the alt alone", () => {
 		const { html } = renderMarkdown("![a|b](https://example.com/x.png)");
 		expect(html).toContain('alt="a|b"');
-- 
2.51.2