fix(scripts): bound control UI i18n process output

test/scripts/control-ui-i18n.test.ts

@@ -0,0 +1,40 @@
+import process from "node:process";
+import { describe, expect, it } from "vitest";
+import { appendBoundedProcessOutput, runProcess } from "../../scripts/control-ui-i18n.ts";
+
+describe("control-ui-i18n process runner", () => {
+  it("keeps a bounded process output tail", () => {
+    const first = appendBoundedProcessOutput({ text: "", truncatedChars: 0 }, "abcdef", 5);
+    const second = appendBoundedProcessOutput(first, "ghij", 5);
+
+    expect(first).toEqual({ text: "bcdef", truncatedChars: 1 });
+    expect(second).toEqual({ text: "fghij", truncatedChars: 5 });
+  });
+
+  it("bounds failure diagnostics to the newest output", async () => {
+    await expect(
+      runProcess(
+        process.execPath,
+        [
+          "-e",
+          [
+            "process.stderr.write('stderr-begin-' + 'x'.repeat(128) + '-stderr-end', () => process.exit(2));",
+          ].join(" "),
+        ],
+        { maxOutputChars: 64, rejectOnFailure: true },
+      ),
+    ).rejects.toThrow(/output truncated[\s\S]*stderr-end/u);
+  });
+
+  it("rejects successful commands before returning truncated stdout", async () => {
+    await expect(
+      runProcess(
+        process.execPath,
+        ["-e", "process.stdout.write('x'.repeat(128), () => process.exit(0));"],
+        {
+          maxOutputChars: 12,
+        },
+      ),
+    ).rejects.toThrow("produced more than 12 stdout chars");
+  });
+});

test/scripts/test-projects.test.ts

@@ -207,6 +207,13 @@ describe("scripts/test-projects changed-target routing", () => {
     });
   });
 
+  it("routes control UI i18n script changes through its regression test", () => {
+    expect(resolveChangedTestTargetPlan(["scripts/control-ui-i18n.ts"])).toEqual({
+      mode: "targets",
+      targets: ["test/scripts/control-ui-i18n.test.ts"],
+    });
+  });
+
   it("routes group visible reply config changes through channel delivery regressions", () => {
     expect(
       resolveChangedTestTargetPlan([