test: use documentation tests (#9)

Author: ryuapp

deno.json

@@ -6,6 +6,7 @@
     "./cli": "./src/cli.ts"
   },
   "tasks": {
+    "test": "deno test --doc -A",
     "cli": "deno run --allow-read --allow-write --allow-env --allow-net=0.0.0.0,127.0.0.1 --allow-run ./src/cli.ts --",
     "dev": "deno run --allow-read --allow-write --allow-env --allow-net=0.0.0.0,127.0.0.1 --allow-run ./src/cli.ts -- README.md",
     "dev:all": "deno run --allow-read --allow-write --allow-env --allow-net=0.0.0.0,127.0.0.1 --allow-run ./src/cli.ts -w --stylesheet=src/testdata/bluecode.css -- README.md",

src/utils/filename.ts

@@ -1,7 +1,16 @@
 /**
  * Get a filename without extname from path.
  *
- * @param path
+ * @example
+ * ```ts
+ * import { assertEquals } from "@std/assert";
+ *
+ * assertEquals(getFilename("README.md"), "README");
+ * assertEquals(getFilename("/README.md"), "/README");
+ * assertEquals(getFilename("./README.md"), "./README");
+ * assertEquals(getFilename("../README.md"), "../README");
+ * assertEquals(getFilename("README.2.md"), "README.2");
+ * ```
  */
 export function getFilename(path: string): string {
   return path.split(".").slice(0, -1).join(".");