super(messageBuilderFactory, secDispatcher);
    }

    @Override
    protected int doExecute(EncryptContext context) throws Exception {
        String cleartext = context.reader.readLine("Enter the password to encrypt: ", '*');
        context.terminal.writer().println(secDispatcher.encrypt(cleartext, null));
        return OK;
    }

    }

    @Test
    @DisplayName("readLine(): reads until newline and handles CRLF")
    void readLine_reads() throws Exception {
        SmbRandomAccessFile raf = spy(newInstance("r", false, false, false));
        // Sequence: 'a','b','\r','\n','c','\n'
        when(raf.read()).thenReturn((int) 'a', (int) 'b', (int) '\r', (int) '\n');
        assertEquals("ab", raf.readLine());

  @CanIgnoreReturnValue // to skip a line
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  public String readLine() {
    throw new UnsupportedOperationException("readLine is not supported");
  }

  @Override
  public void readFully(byte[] b) throws IOException {
    ByteStreams.readFully(this, b);
  }

  @Override

            String line;
            Character detectedDelimiter = delimiter;

            // Read header row if needed
            if (hasHeader) {
                while ((line = reader.readLine()) != null) {
                    if (StringUtil.isBlank(line)) {
                        continue;
                    }
                    // Auto-detect delimiter from first non-blank line

        assertArgumentNotNull("reader", reader);
        this.reader = reader;
    }

    @Override
    public boolean hasNext() {
        if (line == EMPTY) {
            line = ReaderUtil.readLine(reader);
        }
        return line != null;
    }

    @Override
    public String next() {
        if (!hasNext()) {
            throw new NoSuchElementException();
        }

Probablemente quieras probar el proveedor externo una vez, pero no necesariamente llamarlo para cada test que se realice.

En este caso, puedes sobrescribir la dependencia que llama a ese proveedor y usar una dependencia personalizada que devuelva un usuario de prueba, solo para tus tests.

        StringBuilder builder = new StringBuilder();
        try {
            BufferedReader reader = new BufferedReader(new StringReader(rawCommentText));
            String line;
            while ((line = reader.readLine()) != null) {
                line = line.replaceFirst("\\s*\\* ?", "");
                if (line.startsWith("@")) {
                    // Ignore the tag section of the comment
                    break;

  @Override
  float readFloat();

  @CanIgnoreReturnValue // to skip some bytes
  @Override
  double readDouble();

  @CanIgnoreReturnValue // to skip a line
  @Override
  @Nullable String readLine();

  @CanIgnoreReturnValue // to skip a field
  @Override
  String readUTF();

                Thread.currentThread().getContextClassLoader().getResourceAsStream("suggest_settings/default-badwords.txt")))) {

            String line;
            while ((line = br.readLine()) != null) {
                if (line.length() > 0 && !line.startsWith("#")) {
                    list.add(line.trim());
                }
            }
        } catch (final Exception e) {

   */
  public static List<String> readLines(Readable r) throws IOException {
    List<String> result = new ArrayList<>();
    LineReader lineReader = new LineReader(r);
    String line;
    while ((line = lineReader.readLine()) != null) {
      result.add(line);
    }
    return result;
  }

  /**
   * Streams lines from a {@link Readable} object, stopping when the processor returns {@code false}