From 2eb7e25854000090bdb3a8729aed3c3c1f06e381 Mon Sep 17 00:00:00 2001
From: Zef Hemel <zef@zef.me>
Date: Sat, 6 Jul 2024 15:07:40 +0200
Subject: [PATCH] Parse YAML dates into strings

---
 common/settings.ts          |  4 ++--
 plug-api/lib/frontmatter.ts |  5 +++--
 plug-api/lib/json.test.ts   |  8 ++++----
 plug-api/lib/json.ts        | 35 +++++++++++++++++++++++++++++++----
 website/CHANGELOG.md        |  1 +
 5 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/common/settings.ts b/common/settings.ts
index dd100101..7ec4cab4 100644
--- a/common/settings.ts
+++ b/common/settings.ts
@@ -1,7 +1,7 @@
 import YAML from "js-yaml";
 import { INDEX_TEMPLATE, SETTINGS_TEMPLATE } from "./PAGE_TEMPLATES.ts";
 import { SpacePrimitives } from "./spaces/space_primitives.ts";
-import { expandPropertyNames } from "../plug-api/lib/json.ts";
+import { cleanupJSON } from "../plug-api/lib/json.ts";
 import type { BuiltinSettings } from "../type/web.ts";
 
 const yamlSettingsRegex = /^(```+|~~~+)ya?ml\r?\n([\S\s]+?)\1/m;
@@ -97,6 +97,6 @@ export async function ensureAndLoadSettingsAndIndex(
   }
 
   const settings: any = parseYamlSettings(settingsText);
-  expandPropertyNames(settings);
+  cleanupJSON(settings);
   return { ...defaultSettings, ...settings };
 }
diff --git a/plug-api/lib/frontmatter.ts b/plug-api/lib/frontmatter.ts
index 06f33f0d..ca4b39af 100644
--- a/plug-api/lib/frontmatter.ts
+++ b/plug-api/lib/frontmatter.ts
@@ -5,7 +5,7 @@ import {
   replaceNodesMatchingAsync,
   traverseTreeAsync,
 } from "./tree.ts";
-import { expandPropertyNames } from "./json.ts";
+import { cleanupJSON } from "./json.ts";
 import { YAML } from "../syscalls.ts";
 
 export type FrontMatter = { tags?: string[] } & Record<string, any>;
@@ -73,6 +73,7 @@ export async function extractFrontmatter(
       const yamlText = renderToText(yamlNode);
       try {
         const parsedData: any = await YAML.parse(yamlText);
+        console.log("Parsed front matter", parsedData);
         const newData = { ...parsedData };
         data = { ...data, ...parsedData };
         // Make sure we have a tags array
@@ -130,7 +131,7 @@ export async function extractFrontmatter(
 
   // console.log("Extracted tags", data.tags);
   // Expand property names (e.g. "foo.bar" => { foo: { bar: true } })
-  data = expandPropertyNames(data);
+  data = cleanupJSON(data);
 
   return data;
 }
diff --git a/plug-api/lib/json.test.ts b/plug-api/lib/json.test.ts
index dbf1c4e4..9d8ebbc3 100644
--- a/plug-api/lib/json.test.ts
+++ b/plug-api/lib/json.test.ts
@@ -1,5 +1,5 @@
 import { assertEquals } from "$std/testing/asserts.ts";
-import { deepEqual, deepObjectMerge, expandPropertyNames } from "./json.ts";
+import { cleanupJSON, deepEqual, deepObjectMerge } from "./json.ts";
 
 Deno.test("utils", () => {
   assertEquals(deepEqual({ a: 1 }, { a: 1 }), true);
@@ -11,11 +11,11 @@ Deno.test("utils", () => {
   assertEquals(deepObjectMerge({ a: { b: 1 } }, { a: { c: 2 } }), {
     a: { b: 1, c: 2 },
   });
-  assertEquals(expandPropertyNames({ "a.b": 1 }), { a: { b: 1 } });
-  assertEquals(expandPropertyNames({ a: { "a.b": 1 } }), {
+  assertEquals(cleanupJSON({ "a.b": 1 }), { a: { b: 1 } });
+  assertEquals(cleanupJSON({ a: { "a.b": 1 } }), {
     a: { a: { b: 1 } },
   });
-  assertEquals(expandPropertyNames({ a: [{ "a.b": 1 }] }), {
+  assertEquals(cleanupJSON({ a: [{ "a.b": 1 }] }), {
     a: [{ a: { b: 1 } }],
   });
 });
diff --git a/plug-api/lib/json.ts b/plug-api/lib/json.ts
index 7bb56758..0c3d4432 100644
--- a/plug-api/lib/json.ts
+++ b/plug-api/lib/json.ts
@@ -34,8 +34,31 @@ export function deepEqual(a: any, b: any): boolean {
   return false;
 }
 
-// Expands property names in an object containing a .-separated path
-export function expandPropertyNames(a: any): any {
+// Converts a Date object to a date string in the format YYYY-MM-DD if it just contains a date (and no significant time), or a full ISO string otherwise
+export function cleanStringDate(d: Date): string {
+  function pad(n: number) {
+    let s = String(n);
+    if (s.length === 1) {
+      s = "0" + s;
+    }
+    return s;
+  }
+
+  // If no significant time, return a date string only
+  if (
+    d.getUTCHours() === 0 && d.getUTCMinutes() === 0 && d.getUTCSeconds() === 0
+  ) {
+    return d.getFullYear() + "-" + pad(d.getMonth() + 1) + "-" +
+      pad(d.getDate());
+  } else {
+    return d.toISOString();
+  }
+}
+
+// Processes a JSON (typically coming from parse YAML frontmatter) in two ways:
+// 1. Expands property names in an object containing a .-separated path
+// 2. Converts dates to strings in sensible ways
+export function cleanupJSON(a: any): any {
   if (!a) {
     return a;
   }
@@ -43,7 +66,11 @@ export function expandPropertyNames(a: any): any {
     return a;
   }
   if (Array.isArray(a)) {
-    return a.map(expandPropertyNames);
+    return a.map(cleanupJSON);
+  }
+  // If a is a date, convert to a string
+  if (a instanceof Date) {
+    return cleanStringDate(a);
   }
   const expanded: any = {};
   for (const key of Object.keys(a)) {
@@ -56,7 +83,7 @@ export function expandPropertyNames(a: any): any {
       }
       target = target[part];
     }
-    target[parts[parts.length - 1]] = expandPropertyNames(a[key]);
+    target[parts[parts.length - 1]] = cleanupJSON(a[key]);
   }
   return expanded;
 }
diff --git a/website/CHANGELOG.md b/website/CHANGELOG.md
index bbb181ab..60ed7589 100644
--- a/website/CHANGELOG.md
+++ b/website/CHANGELOG.md
@@ -15,6 +15,7 @@ _These features are not yet properly released, you need to use [the edge builds]
 * Improved selection behavior (by [MrMugame](https://github.com/silverbulletmd/silverbullet/pull/904))
 * Hide `\` escapes in [[Live Preview]] (by [MrMugame](https://github.com/silverbulletmd/silverbullet/pull/901))
 * Added Erlang [[Markdown/Syntax Highlighting]]
+* Dates (formatted as e.g. `2023-07-01` or `2023-07-01 23:33`) in [[Frontmatter]] are now converted into strings (rather than empty objects)
 * Numerous other bug fixes (thanks MrMugame and onespaceman)
   
 ---