Use correct length for GString substrings

[timtebeek]

What's changed?

For GString substrings restore the length calculations we saw before b1cb470, as this negatively affected projects using Groovy 2.5, or by extension Gradle 5 or 6.

What's your motivation?

Restore successful parsing for Gradle 5 and 6 projects that use GStrings.

Have you considered any alternatives or workarounds?

Any additional context

This was a bit tricky to test, since we use the latest Groovy in rewrite-groovy. I was able to unit test this by adding a quick sample project:

plugins {
    id("org.openrewrite.build.language-library")
}

dependencies {
    implementation(project(":rewrite-groovy"))
    implementation(project(":rewrite-test"))
    implementation('org.codehaus.groovy:groovy:2.5.23')
}

And adding some unit tests there:

package org.openrewrite.groovy.test;

import org.junit.jupiter.api.Test;
import org.openrewrite.FindParseFailures;
import org.openrewrite.groovy.GroovyParser;
import org.openrewrite.test.RecipeSpec;
import org.openrewrite.test.RewriteTest;

import static org.openrewrite.groovy.Assertions.groovy;

class StringOffByOneTest implements RewriteTest {

    @Override
    public void defaults(RecipeSpec spec) {
        spec
          .parser(GroovyParser.builder())
          .recipe(new FindParseFailures(null, null, null));
    }

    @Test
    void plain() {
        rewriteRun(
          groovy(
            """
              def projectDir = "project"
              def location = "src/main/webapp"
              """
          )
        );
    }

    @Test
    void curlyBraced() {
        rewriteRun(
          groovy(
            """
              def projectDir = "project"
              def location = "${projectDir}-src/main/webapp"
              """
          )
        );
    }

    @Test
    void omittedCurlyBraces() {
        rewriteRun(
          groovy(
            """
              def projectDir = "project"
              def location = "$projectDir-src/main/webapp"
              """
          )
        );
    }


    @Test
    void slashyStringStartCharInRegularString() {
        rewriteRun(
          groovy(
            """
              def projectDir = "project"
              def location = "$projectDir/src/main/webapp"
              """
          )
        );
    }

    @Test
    void slashyString() { // Fails still
        rewriteRun(
          groovy(
            """
              def projectDir = "project"
              def location = /\\/folder/
              """
          )
        );
    }
}

We might want to consider adding a separate module using Groovy 2.5.+ for the purpose of catching these regressions.

[timtebeek]

Copying this existing test to my sample project also works to replicate the issue & fix.

rewrite/rewrite-groovy/src/test/java/org/openrewrite/groovy/tree/LiteralTest.java

Line 31 in b1cb470

class LiteralTest implements RewriteTest {