Unexpected behaviour from `indentWithSpaces(int)`

Given the following build script and Java file on Gradle 3.2.1: build.gradle

plugins {
    id 'java'
    id 'com.diffplug.gradle.spotless' version '2.4.0'
}

group 'org.jbduncan'
version '1.0-SNAPSHOT'

sourceCompatibility = 1.8

repositories {
    mavenCentral()
}

spotless {
    format('example') {
        target '**/*.java'
        indentWithSpaces(4)
    }
}

src/main/java/HelloWorld.java

public final class HelloWorld {
      public String greeting() {
        return "Hello, world!";
    }
}

…I would have expected the Java file to turn into:

public final class HelloWorld {
    public String greeting() {
        return "Hello, world!";
    }
}

or:

public final class HelloWorld {
        public String greeting() {
        return "Hello, world!";
    }
}

…but it seems it doesn’t.

Have I misunderstood what indentWithSpaces(4) is supposed to do here? I understand that it turns all tab indents into 4-space indents, but by my intuitive understanding it should also make sure that all space-indents have a number of spaces equal to a multiple of 4.

[kekko1212]

Yeah I was thinking to help tbh. I have a lot of spare time these days, so, why not contributing to OS? 😄

Thanks for the info, I’ll see if I can get a PR anytime soon. Would be my pleasure.

[nedtwigg]

At first glance, the behavior you expect would be better than the behavior it actually has. But consider this case:

/**
 * An implementation of this class specifies a single step in a formatting process.
 *
 * The input is guaranteed to have unix-style newlines, and the output is required
 * to not introduce any windows-style newlines as well.
 */
public interface FormatterStep extends Serializable {
    ...
}

The behavior you expect would clobber those leading spaces, which seem to be the appropriate formatting even for indentWithTabs(). Many languages with block comments have indentation exceptions which are difficult to code in a general-purpose way.

So the current behavior is to just ensure that if the formatting looks right, then it is right. Tabs and spaces are invisible, so you can’t see if you used the right one. With the current behavior, so long as it looks right, spotless will make sure that you used the right characters, and if you used the wrong one, it can swap it for you automatically.

I’m open to a more powerful compromise if we think of one 😃