Terminal: measure characters with Unicode 11 widths, so an emoji takes the two columns the remote counts

tests/DodoSSH.Client.Terminal.Tests/Renderer/renderer-harness.js

@@ -203,12 +203,22 @@ function FakeTerminal(options) {
   this.focuses = 0;
   this.disposed = false;
   this.pane = null;
+  this.addons = [];
+
+  // The proposed unicode API, at xterm's own default, so a test can see which table the page picked.
+  this.unicode = { activeVersion: '6' };
 
   terminals.push(this);
 }
 
-FakeTerminal.prototype.loadAddon = function () {};
-FakeTerminal.prototype.open = function (pane) { this.pane = pane; };
+FakeTerminal.prototype.loadAddon = function (addon) { this.addons.push(addon); };
+FakeTerminal.prototype.open = function (pane) {
+  this.pane = pane;
+
+  // Taken at open() because that is when the first frame is laid out: a table chosen afterwards would leave
+  // whatever was drawn first measured with the old one.
+  this.unicodeAtOpen = this.unicode.activeVersion;
+};
 FakeTerminal.prototype.attachCustomKeyEventHandler = function (handler) { this.keys = handler; };
 FakeTerminal.prototype.onData = function (handler) { this.data = handler; };
 FakeTerminal.prototype.onResize = function (handler) { this.resized = handler; };
@@ -242,6 +252,12 @@ var FitAddon = {
   },
 };
 
+var Unicode11Addon = {
+  Unicode11Addon: function () {
+    this.kind = 'unicode11';
+  },
+};
+
 var WebglAddon = {
   WebglAddon: function () {
     this.onContextLoss = function () {};
@@ -489,6 +505,16 @@ function typed(sessionId) {
   return terminalFor(sessionId).inputs.join('|');
 }
 
+/** Which character-width table the pane was opened with. */
+function unicodeAtOpen(sessionId) {
+  return terminalFor(sessionId).unicodeAtOpen;
+}
+
+/** Whether that pane loaded the Unicode 11 addon. */
+function hasUnicode11(sessionId) {
+  return terminalFor(sessionId).addons.some(function (addon) { return addon.kind === 'unicode11'; });
+}
+
 /** How many times that pane has been asked for the caret. */
 function focuses(sessionId) {
   return terminalFor(sessionId).focuses;