Improve README loading code

app/controllers/crate/version.js

@@ -127,27 +127,24 @@ export default Controller.extend({
     return data;
   }),
 
+  readme: alias('loadReadmeTask.last.value'),
+
   loadReadmeTask: task(function* () {
-    if (this.currentVersion.get('readme_path')) {
-      try {
-        let r = yield fetch(this.currentVersion.get('readme_path'));
-        if (r.ok) {
-          this.crate.set('readme', yield r.text());
-
-          if (typeof document !== 'undefined') {
-            setTimeout(() => {
-              let e = document.createEvent('CustomEvent');
-              e.initCustomEvent('hashchange', true, true);
-              window.dispatchEvent(e);
-            });
-          }
-        } else {
-          this.crate.set('readme', null);
-        }
-      } catch (error) {
-        this.crate.set('readme', null);
-      }
+    let version = this.currentVersion;
+
+    let readme = version.loadReadmeTask.lastSuccessful
+      ? version.loadReadmeTask.lastSuccessful.value
+      : yield version.loadReadmeTask.perform();
+
+    if (typeof document !== 'undefined') {
+      setTimeout(() => {
+        let e = document.createEvent('CustomEvent');
+        e.initCustomEvent('hashchange', true, true);
+        window.dispatchEvent(e);
+      });
     }
+
+    return readme;
   }),
 
   documentationLink: computed(

app/models/version.js

@@ -39,4 +39,15 @@ export default Model.extend({
 
     return { normal, build, dev };
   }).keepLatest(),
+
+  loadReadmeTask: task(function* () {
+    if (this.readme_path) {
+      let response = yield fetch(this.readme_path);
+      if (!response.ok) {
+        throw new Error(`README request for ${this.crateName} v${this.num} failed`);
+      }
+
+      return yield response.text();
+    }
+  }).keepLatest(),
 });

app/routes/crate/version.js

@@ -62,7 +62,9 @@ export default Route.extend({
     this._super(...arguments);
 
     model.version.loadDepsTask.perform();
-    controller.loadReadmeTask.perform();
+    controller.loadReadmeTask.perform().catch(() => {
+      // ignored
+    });
 
     let { crate } = model;
     if (!crate.documentation || crate.documentation.startsWith('https://docs.rs/')) {

app/templates/crate/version.hbs

@@ -56,9 +56,9 @@
           <CrateTomlCopy @copyText={{this.crateTomlText}} />
         {{/if}}
       </div>
-      {{#if this.crate.readme}}
+      {{#if this.readme}}
         <section local-class="crate-readme" aria-label="Readme" {{highlight-syntax selector="pre > code"}}>
-          {{html-safe this.crate.readme}}
+          {{html-safe this.readme}}
         </section>
       {{else}}
         {{#if this.crate.description}}