More ways to define tags in frontmatter

plug-api/lib/cheap_yaml.test.ts

@@ -0,0 +1,16 @@
+import { assertEquals } from "../../test_deps.ts";
+import { determineTags } from "./cheap_yaml.ts";
+
+Deno.test("cheap yaml", () => {
+  assertEquals([], determineTags(""));
+  assertEquals([], determineTags("hank: bla"));
+  assertEquals(["template"], determineTags("tags: template"));
+  assertEquals(["bla", "template"], determineTags("tags: bla,template"));
+  assertEquals(["bla", "template"], determineTags("tags:\n- bla\n- template"));
+  assertEquals(["bla", "template"], determineTags(`tags: "#bla,#template"`));
+  assertEquals(["bla", "template"], determineTags(`tags: '#bla, #template'`));
+  assertEquals(
+    ["bla", "template"],
+    determineTags(`tags:\n- "#bla"\n- template`),
+  );
+});

plug-api/lib/cheap_yaml.ts

@@ -0,0 +1,36 @@
+const yamlKvRegex = /^\s*(\w+):\s*["']?([^'"]*)["']?$/;
+const yamlListItemRegex = /^\s*-\s+["']?([^'"]+)["']?$/;
+
+/**
+ * Cheap YAML parser to determine tags (ugly, regex based but fast)
+ * @param yamlText
+ * @returns
+ */
+export function determineTags(yamlText: string): string[] {
+  const lines = yamlText.split("\n");
+  let inTagsSection = false;
+  const tags: string[] = [];
+  for (const line of lines) {
+    const yamlKv = yamlKvRegex.exec(line);
+    if (yamlKv) {
+      const [key, value] = yamlKv.slice(1);
+      // Looking for a 'tags' key
+      if (key === "tags") {
+        inTagsSection = true;
+        // 'template' there? Yay!
+        if (value) {
+          tags.push(
+            ...value.split(/,\s*|\s+/).map((t) => t.replace(/^#/, "")),
+          );
+        }
+      } else {
+        inTagsSection = false;
+      }
+    }
+    const yamlListem = yamlListItemRegex.exec(line);
+    if (yamlListem && inTagsSection) {
+      tags.push(yamlListem[1].replace(/^#/, ""));
+    }
+  }
+  return tags;
+}

plug-api/lib/frontmatter.ts

@@ -62,10 +62,14 @@ export async function extractFrontmatter(
         if (!data.tags) {
           data.tags = [];
         }
-        // Normalize tags to an array and support a "tag1, tag2" notation
+        // Normalize tags to an array
+        // support "tag1, tag2" as well as "tag1 tag2" as well as "#tag1 #tag2" notations
         if (typeof data.tags === "string") {
-          data.tags = (data.tags as string).split(/,\s*/);
+          data.tags = (data.tags as string).split(/,\s*|\s+/);
         }
+
+        // Strip # from tags
+        data.tags = data.tags.map((t) => t.replace(/^#/, ""));
         if (options.removeKeys && options.removeKeys.length > 0) {
           let removedOne = false;