LineIteratorTest

package com.moozvine.strings;

import com.moozvine.testing.Verify;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

import java.util.Iterator;

public class LineIteratorTest {
  @Rule public Verify verify = new Verify();
  @Rule public ExpectedException expectedException = ExpectedException.none();


  @Test
  public void stringIteratorWithMultipleLinesShouldReturnAllLines() {
    final Iterator<String> lines = LineIterator.of("one\ntwo\nthree");
    verify.isTrue(lines.hasNext());
    verify.areEqual("one", lines.next());
    verify.isTrue(lines.hasNext());
    verify.areEqual("two", lines.next());
    verify.isTrue(lines.hasNext());
    verify.areEqual("three", lines.next());
    verify.isFalse(lines.hasNext());
  }

  @Test
  public void stringIteratorWithSingleLinesShouldReturnOneLine() {
    final Iterator<String> lines = LineIterator.of("one\ttwo\tthree");
    verify.isTrue(lines.hasNext());
    verify.areEqual("one\ttwo\tthree", lines.next());
    verify.isFalse(lines.hasNext());
  }

  @Test
  public void emptyStringIteratorShouldReturnOneEmptyLine() {
    final Iterator<String> lines = LineIterator.of("");
    verify.isTrue(lines.hasNext());
    verify.areEqual("", lines.next());
    verify.isFalse(lines.hasNext());
  }

  @Test
  public void stringIteratorShouldNotSupportRemoval() {
    final Iterator<String> lines = LineIterator.of("one\ntwo\nthree");
    verify.isTrue(lines.hasNext());
    verify.areEqual("one", lines.next());
    expectedException.expect(UnsupportedOperationException.class);
    lines.remove();
  }

  @Test
  public void stringBuilderIteratorWithMultipleLinesShouldReturnAllLines() {
    final Iterator<String> lines = LineIterator.of(new StringBuilder("one\ntwo\nthree"));
    verify.isTrue(lines.hasNext());
    verify.areEqual("one", lines.next());
    verify.isTrue(lines.hasNext());
    verify.areEqual("two", lines.next());
    verify.isTrue(lines.hasNext());
    verify.areEqual("three", lines.next());
    verify.isFalse(lines.hasNext());
  }

  @Test
  public void stringBuilderIteratorWithSingleLinesShouldReturnOneLine() {
    final Iterator<String> lines = LineIterator.of(new StringBuilder("one\ttwo\tthree"));
    verify.isTrue(lines.hasNext());
    verify.areEqual("one\ttwo\tthree", lines.next());
    verify.isFalse(lines.hasNext());
  }

  @Test
  public void emptyStringBuilderIteratorShouldReturnOneEmptyLine() {
    final Iterator<String> lines = LineIterator.of(new StringBuilder());
    verify.isTrue(lines.hasNext());
    verify.areEqual("", lines.next());
    verify.isFalse(lines.hasNext());
  }

  @Test
  public void stringBuilderIteratorWithMultipleLinesShouldSupportFirstLineRemoval() {
    final StringBuilder stringBuilder = new StringBuilder("one\nand two\nand three");
    final Iterator<String> lines = LineIterator.of(stringBuilder);
    verify.isTrue(lines.hasNext());
    verify.areEqual("one", lines.next());
    lines.remove();
    verify.isTrue(lines.hasNext());
    verify.areEqual("and two", lines.next());
    verify.isTrue(lines.hasNext());
    verify.areEqual("and three", lines.next());
    verify.isFalse(lines.hasNext());
    verify.areEqual("and two\nand three", stringBuilder.toString());
  }

  @Test
  public void stringBuilderIteratorWithMultipleLinesShouldSupportMiddleLineRemoval() {
    final StringBuilder stringBuilder = new StringBuilder("one\nand two\nand three");
    final Iterator<String> lines = LineIterator.of(stringBuilder);
    verify.isTrue(lines.hasNext());
    verify.areEqual("one", lines.next());
    verify.isTrue(lines.hasNext());
    verify.areEqual("and two", lines.next());
    lines.remove();
    verify.isTrue(lines.hasNext());
    verify.areEqual("and three", lines.next());
    verify.isFalse(lines.hasNext());
    verify.areEqual("one\nand three", stringBuilder.toString());
  }

  @Test
  public void stringBuilderIteratorWithMultipleLinesShouldSupportLastLineRemoval() {
    final StringBuilder stringBuilder = new StringBuilder("one\nand two\nand three");
    final Iterator<String> lines = LineIterator.of(stringBuilder);
    verify.isTrue(lines.hasNext());
    verify.areEqual("one", lines.next());
    verify.isTrue(lines.hasNext());
    verify.areEqual("and two", lines.next());
    verify.isTrue(lines.hasNext());
    verify.areEqual("and three", lines.next());
    lines.remove();
    verify.isFalse(lines.hasNext());
    verify.areEqual("one\nand two\n", stringBuilder.toString());
  }
}