Syntax fixes (#5367)

* Declare return types on functions

And a very few other type related minor fixes

* Minor syntax fixes

* Remove unnecessary escape chars in regexes
* Remove unnecessary awaits
* Replace deprecated req.connection with req.socket
* Replace deprecated upload with uploadOne
* Remove unnecessary eslint-disable-next-line comments
* Comment empty functions / catch or finally clauses
* Fix irregular whitespaces
* Add missing returns (null)
* Remove unreachable code
* A few logical fixes
* Remove / Handle non-null assertions which are certainly unnecessary (e.g. in
tests)

app/src/utils/render-string-template.ts

@@ -1,21 +1,28 @@
-import { computed, Ref } from '@vue/composition-api';
+import { computed, ComputedRef, Ref } from '@vue/composition-api';
 import { render } from 'micromustache';
 import { getFieldsFromTemplate } from './get-fields-from-template';
 
+type StringTemplate = {
+	fieldsInTemplate: ComputedRef<string[]>;
+	displayValue: ComputedRef<string | false>;
+};
+
 export function renderStringTemplate(
 	template: Ref<string | null> | string,
 	item: Ref<Record<string, any> | undefined | null>
-) {
+): StringTemplate {
 	const templateString = computed(() => (typeof template === 'string' ? template : template.value));
 
 	const fieldsInTemplate = computed(() => getFieldsFromTemplate(templateString.value));
 
 	const displayValue = computed(() => {
-		if (!item.value || !templateString.value || !fieldsInTemplate.value) return;
+		if (!item.value || !templateString.value || !fieldsInTemplate.value) return false;
 
 		try {
 			return render(templateString.value, item.value, { propsExist: true });
-		} catch {}
+		} catch {
+			return false;
+		}
 	});
 
 	return { fieldsInTemplate, displayValue };