#48: improve history behavior

Author: Jorik De Waen

src/main/java/com/flowingcode/vaadin/addons/xterm/TerminalHistory.java

@@ -98,7 +98,10 @@ public void setEnabled(boolean enabled) {
       registrations = null;
     } else if (enabled && registrations == null) {
       registrations = new ArrayList<>();
-      registrations.add(((ITerminalConsole) terminal).addLineListener(ev -> add(ev.getLine())));
+      registrations.add(((ITerminalConsole) terminal).addLineListener(ev -> {
+        add(ev.getLine());
+        resetIterator();
+      }));
       registrations.add(terminal.addCustomKeyListener(ev -> handleArrowUp(), Key.ARROW_UP));
       registrations.add(terminal.addCustomKeyListener(ev -> handleArrowDown(), Key.ARROW_DOWN));
     }
@@ -168,13 +171,19 @@ public void add(String line) {
     line = line.trim();
     if (!line.isEmpty()) {
       history.add(Objects.requireNonNull(line));
-      iterator = null;
+      resetIterator();
       if (maxSize != null && history.size() > maxSize) {
         history.removeLast();
       }
     }
   }
 
+  private void resetIterator()
+  {
+    lastRet = null;
+    iterator = null;
+  }
+
   private Optional<String> find(Iterator<String> iterator, Predicate<String> predicate) {
     while (iterator.hasNext()) {
       String line = iterator.next();

src/test/java/com/flowingcode/vaadin/addons/xterm/integration/TerminalHistoryIT.java

@@ -71,4 +71,44 @@ public void testArrowKeysAndRestore() {
     assertThat(term.currentLine(), is("bar"));
   }
 
+  @Test
+  public void testArrowUpAfterRunningLastCommandFromHistory() {
+    XTermElement term = $(XTermElement.class).first();
+
+    term.sendKeys("foo1\n");
+    term.sendKeys("foo2\n");
+
+    assertThat(term.currentLine(), isEmptyString());
+
+    term.sendKeys(Keys.ARROW_UP);
+    assertThat(term.currentLine(), is("foo2"));
+    term.sendKeys("\n");
+
+    term.sendKeys(Keys.ARROW_UP);
+    assertThat(term.currentLine(), is("foo2"));
+
+    term.sendKeys(Keys.ARROW_UP);
+    assertThat(term.currentLine(), is("foo1"));
+  }
+
+  @Test
+  public void testArrowUpAfterRunningEmptyCommand() {
+    XTermElement term = $(XTermElement.class).first();
+
+    term.sendKeys("foo1\n");
+    term.sendKeys("foo2\n");
+
+    assertThat(term.currentLine(), isEmptyString());
+
+    term.sendKeys(Keys.ARROW_UP);
+    assertThat(term.currentLine(), is("foo2"));
+    term.sendKeys("\u0008\u0008\u0008\u0008"); // 4 backspaces
+    assertThat(term.currentLine(), isEmptyString());
+    term.sendKeys("\n");
+
+    term.sendKeys(Keys.ARROW_UP);
+    // The position in the history should be back at the end
+    assertThat(term.currentLine(), is("foo2"));
+  }
+
 }