allow errors in usercss when saving in editor and live-reloading

background/usercss-helper.js

@@ -4,6 +4,7 @@
 (() => {
 
   API_METHODS.saveUsercss = save;
+  API_METHODS.saveUsercssUnsafe = style => save(style, true);
   API_METHODS.buildUsercss = build;
   API_METHODS.installUsercss = install;
 
@@ -47,60 +48,56 @@
     }
   }
 
-  function buildCode(style) {
-    return usercss.buildCode(style);
-  }
-
   // Parse the source and find the duplication
   function build({sourceCode, checkDup = false}) {
     return buildMeta({sourceCode})
-      .then(style => Promise.all([
-        buildCode(style),
-        checkDup && findDup(style)
-      ]))
-      .then(([style, dup]) => ({style, dup}));
+      .then(usercss.buildCode)
+      .then(style => ({
+        style,
+        dup: checkDup && findDup(style),
+      }));
   }
 
-  function save(style) {
+  function save(style, allowErrors = false) {
     // restore if stripped by getStyleWithNoCode
     if (typeof style.sourceCode !== 'string') {
       style.sourceCode = cachedStyles.byId.get(style.id).sourceCode;
     }
     return buildMeta(style)
       .then(assignVars)
-      .then(buildCode)
-      .then(saveStyle);
+      .then(style => usercss.buildCode(style, allowErrors))
+      .then(result =>
+        allowErrors ?
+          saveStyle(result.style).then(style => ({style, errors: result.errors})) :
+          saveStyle(result));
 
     function assignVars(style) {
       if (style.reason === 'config' && style.id) {
         return style;
       }
-      return findDup(style).then(dup => {
-        if (dup) {
-          style.id = dup.id;
-          if (style.reason !== 'config') {
-            // preserve style.vars during update
-            usercss.assignVars(style, dup);
-          }
+      const dup = findDup(style);
+      if (dup) {
+        style.id = dup.id;
+        if (style.reason !== 'config') {
+          // preserve style.vars during update
+          usercss.assignVars(style, dup);
         }
-        return style;
-      });
+      }
+      return style;
     }
   }
 
   function findDup(style) {
-    if (style.id) {
-      return getStyles({id: style.id}).then(s => s[0]);
+    if (style.id) return cachedStyles.byId.get(style.id);
+    const {name, namespace} = style.usercssData;
+    for (const dup of cachedStyles.list) {
+      const data = dup.usercssData;
+      if (!data) continue;
+      if (data.name === name &&
+          data.namespace === namespace) {
+        return dup;
+      }
     }
-    return getStyles().then(styles =>
-      styles.find(target => {
-        if (!target.usercssData) {
-          return false;
-        }
-        return target.usercssData.name === style.usercssData.name &&
-          target.usercssData.namespace === style.usercssData.namespace;
-      })
-    );
   }
 
   function install({url, direct, downloaded, tab}, sender) {

edit/source-editor.js

@@ -192,13 +192,16 @@ function createSourceEditor(style) {
     if (!dirty.isDirty()) return;
     const code = cm.getValue();
     return (
-      API.saveUsercss({
-        reason: 'editSave',
+      API.saveUsercssUnsafe({
         id: style.id,
+        reason: 'editSave',
         enabled: style.enabled,
         sourceCode: code,
       }))
-      .then(replaceStyle)
+      .then(({style, errors}) => {
+        replaceStyle(style);
+        if (errors) return Promise.reject(errors);
+      })
       .catch(err => {
         if (err.message === t('styleMissingMeta', 'name')) {
           messageBox.confirm(t('usercssReplaceTemplateConfirmation')).then(ok => ok &&

install-usercss/install-usercss.js

@@ -68,13 +68,14 @@
       cm.setCursor(cursor);
       cm.scrollTo(scrollInfo.left, scrollInfo.top);
 
-      return sendMessage({
+      API.saveUsercssUnsafe({
         id: (installed || installedDup).id,
-        method: 'saveUsercss',
         reason: 'update',
         sourceCode
-      }).then(updateMeta)
-        .catch(showError);
+      }).then(({style, errors}) => {
+        updateMeta(style);
+        if (errors) return Promise.reject(errors);
+      }).catch(showError);
     });
   }
 

js/usercss.js

@@ -471,7 +471,13 @@ var usercss = (() => {
     return version;
   }
 
-  function buildCode(style) {
+  /**
+   * @param {Object} style
+   * @param {Boolean} [allowErrors=false]
+   * @returns {(Style | {style: Style, errors: (false|String[])})} - style object
+   *      when allowErrors is falsy or {style, errors} object when allowErrors is truthy
+   */
+  function buildCode(style, allowErrors) {
     const {usercssData: {preprocessor, vars}, sourceCode} = style;
     let builder;
     if (preprocessor) {
@@ -494,11 +500,14 @@ var usercss = (() => {
         styleId: style.id,
         code: mozStyle,
       }))
-      .then(({sections, errors}) => sections.length && sections || Promise.reject(errors))
-      .then(sections => {
+      .then(({sections, errors}) => {
+        if (!errors.length) errors = false;
+        if (!sections.length || errors && !allowErrors) {
+          return Promise.reject(errors);
+        }
         style.sections = sections;
         if (builder.postprocess) builder.postprocess(style.sections, sVars);
-        return style;
+        return allowErrors ? {style, errors} : style;
       }));
   }