1 files changed, 75 insertions, 0 deletions
diff --git a/src/search.ts b/src/search.ts
new file mode 100644
index 000000000..d9e2fa00c
--- /dev/null
+++ b/src/search.ts
@@ -0,0 +1,75 @@
+import { existsSync } from 'fs';
+
+interface PageLocation {
+  fileURL: URL;
+  snowpackURL: string;
+}
+
+function findAnyPage(candidates: Array<string>, astroRoot: URL): PageLocation | false {
+  for(let candidate of candidates) {
+    const url = new URL(`./pages/${candidate}`, astroRoot);
+    if(existsSync(url)) {
+      return {
+        fileURL: url,
+        snowpackURL: `/_astro/pages/${candidate}.js`
+      };
+    }
+  }
+  return false;
+}
+
+type SearchResult = {
+  statusCode: 200;
+  location: PageLocation;
+  pathname: string;
+} | {
+  statusCode: 301;
+  location: null;
+  pathname: string;
+} | {
+  statusCode: 404;
+};
+
+export function searchForPage(url: URL, astroRoot: URL): SearchResult {
+  const reqPath = decodeURI(url.pathname);
+  const base = reqPath.substr(1);
+
+  // Try to find index.astro/md paths
+  if(reqPath.endsWith('/')) {
+    const candidates = [`${base}index.astro`, `${base}index.md`];
+    const location = findAnyPage(candidates, astroRoot);
+    if(location) {
+      return {
+        statusCode: 200,
+        location,
+        pathname: reqPath
+      };
+    }
+  } else {
+    // Try to find the page by its name.
+    const candidates = [`${base}.astro`, `${base}.md`];
+    let location = findAnyPage(candidates, astroRoot);
+    if(location) {
+      return {
+        statusCode: 200,
+        location,
+        pathname: reqPath
+      };
+    }
+  }
+
+  // Try to find name/index.astro/md
+  const candidates = [`${base}/index.astro`, `${base}/index.md`];
+  const location = findAnyPage(candidates, astroRoot);
+  if(location) {
+    return {
+      statusCode: 301,
+      location: null,
+      pathname: reqPath + '/'
+    };
+  }
+
+  return {
+    statusCode: 404
+  };
+}
+\ No newline at end of file