Invariances

The goal of SemanticDiff is to help you focus on the relevant changes. To achieve this, SemanticDiff tries to hide changes that do not affect the execution of the program. These invariances can be divided into two categories. The first category contains changes that do not modify the program on a syntactic level. This is usually defined by the grammar of the programming language and includes things like line breaks between parameters or optional commas. The second category contains changes that modify the code on a syntactic level but that do not change the semantics of a program. An example would be replacing for(;;) with while(1).

In the following sections we give an overview of the invariances supported by SemanticDiff. We will mainly focus on the second category (semantic equivalence).

C#

Adding/Removing unnecessary parenthesis
Changing the base of an integer literal
Escaping characters in strings

CSS

(Only syntactic equivalence)

Go

Adding/Removing unnecessary parenthesis
Changing the base of an integer literal
Escaping characters in strings
Reordering of type elements in a type term

Java

Adding/Removing unnecessary parenthesis
Changing the base of an integer literal
Escaping characters in strings

JavaScript / JSX

Adding/Removing unnecessary parenthesis
Changing the base of an integer literal
Escaping characters in strings
Reordering keys in an object declaration
Converting between an anonymous/arrow function

JSON5

Changing the base of an integer literal
Escaping characters in strings
Reordering of keys

Gettext .po

Escaping characters in strings
Reordering of messages

Python

Adding/Removing unnecessary parenthesis
Changing the base of an integer literal
Escaping characters in strings
Splitting / combining of strings
Reordering of keyword arguments

Rust

Adding/Removing unnecessary parenthesis
Changing the base of an integer literal
Escaping characters in a string/char
Exchanging the deprecated ... range operator with ..=

SCSS