[Init] Initial commit - NetMesh terminal manager

components/terminal/terminalContextBuffer.test.ts

@@ -0,0 +1,59 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import {
+  readActiveTerminalBufferTextRange,
+  readTerminalBufferTextRange,
+} from "./terminalContextBuffer.ts";
+
+function createBuffer(lines: string[]) {
+  return {
+    getLine(index: number) {
+      const value = lines[index];
+      if (value === undefined) return undefined;
+      return {
+        translateToString(trimRight?: boolean, startColumn = 0, endColumn?: number) {
+          const sliced = value.slice(startColumn, endColumn);
+          return trimRight ? sliced.trimEnd() : sliced;
+        },
+      };
+    },
+  };
+}
+
+test("readTerminalBufferTextRange returns only the requested rows", () => {
+  const buffer = createBuffer([
+    "normal-history",
+    "top header",
+    "cpu  12%",
+    "mem  44%",
+    "bottom prompt",
+  ]);
+
+  assert.equal(
+    readTerminalBufferTextRange(buffer as never, {
+      startLine: 1,
+      endLine: 3,
+      cols: 80,
+    }),
+    "top header\ncpu  12%\nmem  44%",
+  );
+});
+
+test("readActiveTerminalBufferTextRange reads the active alternate buffer without normal scrollback", () => {
+  const normalBuffer = createBuffer(["old normal scrollback"]);
+  const alternateBuffer = createBuffer(["vim title", "file body", ":"]);
+  const term = {
+    cols: 80,
+    buffer: {
+      active: alternateBuffer,
+      normal: normalBuffer,
+      alternate: alternateBuffer,
+    },
+  };
+
+  assert.equal(
+    readActiveTerminalBufferTextRange(term as never, { startLine: 0, endLine: 2 }),
+    "vim title\nfile body\n:",
+  );
+});