diff --git a/src/compiler/preprocess/index.ts b/src/compiler/preprocess/index.ts
index 27c1c471c1..3e2bf99c7c 100644
--- a/src/compiler/preprocess/index.ts
+++ b/src/compiler/preprocess/index.ts
@@ -104,8 +104,9 @@ function get_replacement(
 	let decoded_map: DecodedSourceMap;
 	if (processed.map) {
 		decoded_map = typeof processed.map === 'string' ? JSON.parse(processed.map) : processed.map;
-		if (typeof(decoded_map.mappings) === 'string')
+		if (typeof(decoded_map.mappings) === 'string') {
 			decoded_map.mappings = decode_mappings(decoded_map.mappings);
+		}
 		sourcemap_add_offset(decoded_map, get_location(offset + prefix.length));
 	}
 	const processed_with_map = StringWithSourcemap.from_processed(processed.code, decoded_map);
@@ -146,12 +147,13 @@ export default async function preprocess(
 
 		if (processed && processed.dependencies) dependencies.push(...processed.dependencies);
 		source = processed ? processed.code : source;
-		if (processed && processed.map)
+		if (processed && processed.map) {
 			sourcemap_list.unshift(
 				typeof(processed.map) === 'string'
 					? JSON.parse(processed.map)
 					: processed.map
 			);
+		}
 	}
 
 	for (const fn of script) {
diff --git a/src/compiler/utils/string_with_sourcemap.ts b/src/compiler/utils/string_with_sourcemap.ts
index 845d46ec7d..ebd44221e1 100644
--- a/src/compiler/utils/string_with_sourcemap.ts
+++ b/src/compiler/utils/string_with_sourcemap.ts
@@ -59,8 +59,9 @@ function merge_tables<T>(this_table: T[], other_table): [T[], number[], boolean,
 }
 
 function pushArray<T>(_this: T[], other: T[]) {
-	for (let i = 0; i < other.length; i++)
+	for (let i = 0; i < other.length; i++) {
 		_this.push(other[i]);
+	}
 }
 
 export class StringWithSourcemap {
@@ -69,15 +70,16 @@ export class StringWithSourcemap {
 
 	constructor(string = '', map = null) {
 		this.string = string;
-		if (map)
+		if (map) {
 			this.map = map as DecodedSourceMap;
-		else
+		} else {
 			this.map = {
 				version: 3,
 				mappings: [],
 				sources: [],
 				names: []
 			};
+		}
 	}
 
 	// concat in-place (mutable), return this (chainable)