spring-boot-demo/crud-mysql/src/test/java/com/ankurm/crud/Transcript.java

package com.ankurm.crud;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.nio.file.Files;
import java.nio.file.Path;

/**
 * Writes a numbered transcript under {@code output/} and echoes it to the console.
 * Every console block quoted in the article comes out of one of these files verbatim.
 */
public final class Transcript implements AutoCloseable {

    private final Path path;
    private final StringWriter buffer = new StringWriter();
    private final PrintWriter out = new PrintWriter(buffer);

    public Transcript(String fileName, String title) {
        this.path = Path.of("output", fileName);
        out.println("# " + title);
        out.println();
    }

    public Transcript line(String format, Object... args) {
        out.println(args.length == 0 ? format : String.format(format, args));
        return this;
    }

    public Transcript blank() {
        out.println();
        return this;
    }

    public Transcript section(String heading) {
        out.println();
        out.println("--- " + heading + " ---");
        return this;
    }

    @Override
    public void close() {
        out.flush();
        // Absolute paths of whoever ran the build are environment noise, not a finding.
        String text = buffer.toString().replace(System.getProperty("user.dir"), "<crud-mysql>");
        try {
            Files.createDirectories(path.getParent());
            Files.writeString(path, text);
        } catch (IOException e) {
            throw new IllegalStateException("could not write " + path, e);
        }
        System.out.print(text);
    }
}