terminal: TBC tests

src/terminal/Terminal.zig

@@ -1452,7 +1452,6 @@ pub fn horizontalTabBack(self: *Terminal) !void {
 }
 
 /// Clear tab stops.
-/// TODO: test
 pub fn tabClear(self: *Terminal, cmd: csi.TabClear) void {
     switch (cmd) {
         .current => self.tabstops.unset(self.screen.cursor.x),
@@ -5441,3 +5440,26 @@ test "Terminal: scrollDown left/right scroll region" {
         try testing.expectEqualStrings("A   23\nDBC156\nGEF489\n HI7", str);
     }
 }
+
+test "Terminal: tabClear single" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 30, 5);
+    defer t.deinit(alloc);
+
+    try t.horizontalTab();
+    t.tabClear(.current);
+    t.setCursorPos(1, 1);
+    try t.horizontalTab();
+    try testing.expectEqual(@as(usize, 16), t.screen.cursor.x);
+}
+
+test "Terminal: tabClear all" {
+    const alloc = testing.allocator;
+    var t = try init(alloc, 30, 5);
+    defer t.deinit(alloc);
+
+    t.tabClear(.all);
+    t.setCursorPos(1, 1);
+    try t.horizontalTab();
+    try testing.expectEqual(@as(usize, 29), t.screen.cursor.x);
+}

website/app/vt/tbc/page.mdx

@@ -0,0 +1,47 @@
+import VTSequence from "@/components/VTSequence";
+
+# Tab Clear (TBC)
+
+<VTSequence sequence={["CSI", "Pn", "g"]} />
+
+Clear one or all tab stops.
+
+The parameter `n` must be `0` or `3`. If `n` is omitted, `n` defaults to `0`.
+
+If the parameter `n` is `0`, the cursor column position is marked as
+not a tab stop. If the column was already not a tab stop, this does nothing.
+
+If the parameter `n` is `3`, all tab stops are cleared.
+
+## Validation
+
+### TBC V-1: Tab Clear Single
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "\033[?W" # reset tabs
+printf "\t"
+printf "\033[g"
+printf "\033[1G"
+printf "\t"
+```
+
+```
+|_______________c_______|
+```
+
+### TBC V-3: Clear All Tabstops
+
+```bash
+printf "\033[1;1H" # move to top-left
+printf "\033[0J" # clear screen
+printf "\033[?W" # reset tabs
+printf "\033[3g"
+printf "\033[1G"
+printf "\t"
+```
+
+```
+|______________________c|
+```