fix branch sha, update config

Author: Amelia Wattenberger

blocks.config.json

@@ -1,9 +1,9 @@
 [
   {
     "type": "folder",
-    "id": "preview-block",
+    "id": "preview-folder-block",
     "title": "Preview Block",
-    "description": "Preview your site",
+    "description": "Preview your site (from a folder)",
     "entry": "blocks/preview-folder-block.tsx",
     "matches": ["*"],
     "example_path": "https://github.com/githubnext/blocks-preview-experiment"
@@ -12,7 +12,7 @@
     "type": "file",
     "id": "preview-file-block",
     "title": "Preview Block",
-    "description": "Preview your site",
+    "description": "Preview your site (from a file)",
     "entry": "blocks/preview-file-block.tsx",
     "matches": ["*.tsx, *.ts, *.jsx, *.js"],
     "example_path": "https://github.com/githubnext/blocks-preview-experiment/blob/main/pages/about.tsx"

blocks/preview-file-block.tsx

@@ -28,7 +28,7 @@ export default function (props: FolderBlockProps) {
       src={url}
       style={{
         width: "100%",
-        height: "100%",
+        height: "100vh",
         border: "none",
       }}
     />

blocks/preview-folder-block.tsx

@@ -8,8 +8,11 @@ export default function (props: FolderBlockProps) {
   const url = `https://${context.owner}.github.io/${context.repo}/${sha}`
 
   const updateSha = async () => {
-    if (sha !== "HEAD") return
-    const res = await onRequestGitHubData(`/repos/${context.owner}/${context.repo}/git/refs/heads/main`);
+    const isShaBranchName = context.sha.length !== 40;
+    if (!isShaBranchName) return
+    const res = await onRequestGitHubData(
+      `/repos/${context.owner}/${context.repo}/git/refs/heads/${context.sha}`
+    );
     const defaultSha = res.object.sha
     setSha(defaultSha)
   }
@@ -22,7 +25,7 @@ export default function (props: FolderBlockProps) {
       src={url}
       style={{
         width: "100%",
-        height: "100%",
+        height: "100vh",
         border: "none",
       }}
     />