updateReadme.gradle

import java.nio.charset.Charset
import java.nio.file.Files
import java.nio.file.Paths

/**
 * Reads a file as string.
 *
 * @param path path to the file.
 * @return the string with the file contents.
 * @throws IOException if file don’t exist.
 */
private static String readFileAsString(String path) throws IOException {
    byte[] encoded = Files.readAllBytes(Paths.get(path))
    return new String(encoded, Charset.defaultCharset())
}

/**
 * Replace every semantic version occurrence in  specified file.
 *
 * @param newVersion version to replace.
 * @param fileName the file to search.
 * @throws IOException if file don’t exist.
 */
private static void replaceAllSemVerInFile(String newVersion, String fileName) throws IOException {
    String readme = readFileAsString(fileName)
    String readmeVersionReplaced = readme.replaceAll("(\\d+(\\.\\d+){2})(\\-[\\w\\d\\.\\-]*)?(\\+[\\w\\d\\.\\-]*)?", newVersion)

    PrintWriter output = new PrintWriter(fileName)
    output.print(readmeVersionReplaced)
    output.close()
}

ext {
    processUpdateReadme = { File resDir, String extension, String libraryVersionName ->
        resDir.eachFileRecurse { file ->
            if (file.name.endsWith(extension)) {
                replaceAllSemVerInFile(libraryVersionName, file.absolutePath)
            }
        }
    }
}