Add KillCaller feature to test server for CLI crash recovery testing

Author: varundeepsaini

acceptance/internal/config.go

@@ -156,6 +156,11 @@ type ServerStub struct {
 	// Configure as "1ms", "2s", "3m", etc.
 	// See [time.ParseDuration] for details.
 	Delay time.Duration
+
+	// If set, send this signal to the caller process instead of returning a response.
+	// Use signal numbers: 9 for SIGKILL, 15 for SIGTERM, etc.
+	// Requires DATABRICKS_CLI_TEST_PID=1 to be set.
+	KillCaller int
 }
 
 // FindConfigs finds all the config relevant for this test,

acceptance/internal/prepare_server.go

@@ -10,6 +10,7 @@ import (
 	"slices"
 	"strings"
 	"sync"
+	"syscall"
 	"testing"
 	"time"
 	"unicode/utf8"
@@ -209,6 +210,43 @@ func startLocalServer(t *testing.T,
 				}
 			}
 
+			if stub.KillCaller > 0 {
+				pid := testserver.ExtractPidFromHeaders(req.Headers)
+				if pid == 0 {
+					t.Errorf("KillCaller configured but test-pid not found in User-Agent")
+					return testserver.Response{
+						StatusCode: http.StatusBadRequest,
+						Body:       "test-pid not found in User-Agent (set DATABRICKS_CLI_TEST_PID=1)",
+					}
+				}
+
+				signal := syscall.Signal(stub.KillCaller)
+				t.Logf("KillCaller: sending signal %d to PID %d (pattern: %s)", signal, pid, stub.Pattern)
+
+				process, err := os.FindProcess(pid)
+				if err != nil {
+					t.Errorf("Failed to find process %d: %s", pid, err)
+					return testserver.Response{
+						StatusCode: http.StatusInternalServerError,
+						Body:       fmt.Sprintf("failed to find process: %s", err),
+					}
+				}
+
+				if err := process.Signal(signal); err != nil {
+					t.Errorf("Failed to send signal %d to process %d: %s", signal, pid, err)
+					return testserver.Response{
+						StatusCode: http.StatusInternalServerError,
+						Body:       fmt.Sprintf("failed to send signal: %s", err),
+					}
+				}
+
+				// Return a response (the CLI will likely be killed before it receives this)
+				return testserver.Response{
+					StatusCode: http.StatusOK,
+					Body:       fmt.Sprintf("sent signal %d to PID %d", signal, pid),
+				}
+			}
+
 			return stub.Response
 		})
 	}

acceptance/selftest/kill_caller/mid_request/out.test.toml

@@ -0,0 +1,5 @@
+
+>>> errcode [CLI] workspace list /
+script: line [N]: [PID] Killed                  "$@"
+
+Exit code: 137

acceptance/selftest/kill_caller/mid_request/output.txt

@@ -0,0 +1 @@
+trace errcode $CLI workspace list /

acceptance/selftest/kill_caller/mid_request/script

@@ -0,0 +1,10 @@
+Local = true
+Env.DATABRICKS_CLI_TEST_PID = "1"
+
+[[Server]]
+Pattern = "GET /api/2.0/workspace/list"
+KillCaller = 9
+
+[[Repls]]
+Old = 'script: line \d+: \d+ Killed'
+New = 'script: line [N]: [PID] Killed'

acceptance/selftest/kill_caller/mid_request/test.toml

@@ -0,0 +1,5 @@
+
+>>> errcode [CLI] current-user me
+script: line [N]: [PID] Killed                  "$@"
+
+Exit code: 137

acceptance/selftest/kill_caller/out.test.toml

@@ -0,0 +1 @@
+trace errcode $CLI current-user me

acceptance/selftest/kill_caller/output.txt

@@ -0,0 +1,11 @@
+Local = true
+Env.DATABRICKS_CLI_TEST_PID = "1"
+
+# Kill the CLI when it calls /Me endpoint
+[[Server]]
+Pattern = "GET /api/2.0/preview/scim/v2/Me"
+KillCaller = 9
+
+[[Repls]]
+Old = 'script: line \d+: \d+ Killed'
+New = 'script: line [N]: [PID] Killed'