crate.version: Cache README per version

... instead of the broken per crate caching

Author: Turbo87

app/controllers/crate/version.js

@@ -127,20 +127,24 @@ export default Controller.extend({
     return data;
   }),
 
+  readme: alias('loadReadmeTask.last.value'),
+
   loadReadmeTask: task(function* () {
-    try {
-      this.crate.set('readme', yield this.currentVersion.loadReadmeTask.perform());
-
-      if (typeof document !== 'undefined') {
-        setTimeout(() => {
-          let e = document.createEvent('CustomEvent');
-          e.initCustomEvent('hashchange', true, true);
-          window.dispatchEvent(e);
-        });
-      }
-    } 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/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}}