Better error handling

Models/ThemeConfig/Conversion/Conversion.ts

@@ -216,13 +216,18 @@ export class Fuse<T> extends DesugaringStep<T> {
         const information = []
         for (let i = 0; i < this.steps.length; i++) {
             const step = this.steps[i];
-            let r = step.convert(json, "While running step " + step.name + ": " + context)
-            errors.push(...r.errors ?? [])
-            warnings.push(...r.warnings ?? [])
-            information.push(...r.information ?? [])
-            json = r.result
-            if (errors.length > 0) {
-                break;
+            try{
+                let r = step.convert(json, "While running step " + step.name + ": " + context)
+                errors.push(...r.errors ?? [])
+                warnings.push(...r.warnings ?? [])
+                information.push(...r.information ?? [])
+                json = r.result
+                if (errors.length > 0) {
+                    break;
+                }
+            }catch(e){
+                console.error("Step "+step.name+" failed due to "+e);
+                throw e
             }
         }
         return {

Models/ThemeConfig/Conversion/PrepareTheme.ts

@@ -479,6 +479,7 @@ export class PrepareTheme extends Fuse<LayoutConfigJson> {
     }) {
         super(
             "Fully prepares and expands a theme",
+
             new AddContextToTransltionsInLayout(),
             new PreparePersonalTheme(state),
             new WarnForUnsubstitutedLayersInTheme(),

Models/ThemeConfig/Conversion/Validation.ts

@@ -217,12 +217,17 @@ class MiscThemeChecks extends DesugaringStep<LayoutConfigJson>{
     
     convert(json: LayoutConfigJson, context: string): { result: LayoutConfigJson; errors?: string[]; warnings?: string[]; information?: string[] } {
         const warnings = []
+        const errors = []
+        if(json.id !== "personal" && (json.layers === undefined || json.layers.length === 0)){
+            errors.push("The theme "+json.id+" has no 'layers' defined ("+context+")")
+        }
         if(json.socialImage === ""){
             warnings.push("Social image for theme "+json.id+" is the emtpy string")
         }
         return {
             result :json,
-            warnings
+            warnings,
+            errors
         };
     }
 }
@@ -231,8 +236,8 @@ export class PrevalidateTheme extends Fuse<LayoutConfigJson> {
 
     constructor() {
         super("Various consistency checks on the raw JSON",
-            new OverrideShadowingCheck(),
-            new MiscThemeChecks()
+            new MiscThemeChecks(),
+            new OverrideShadowingCheck()
         );
 
     }