fix: resolve connectionName from store when no --connection flag

Commands now automatically use the last-used connection from
connections.json instead of requiring --connection or -c flag.

src/pbi_cli/commands/_helpers.py

@@ -10,6 +10,16 @@ from pbi_cli.core.output import format_mcp_result, print_error
 from pbi_cli.main import PbiContext
 
 
+def resolve_connection_name(ctx: PbiContext) -> str | None:
+    """Return the connection name from --connection flag or last-used store."""
+    if ctx.connection:
+        return ctx.connection
+    from pbi_cli.core.connection_store import load_connections
+
+    store = load_connections()
+    return store.last_used or None
+
+
 def run_tool(
     ctx: PbiContext,
     tool_name: str,
@@ -22,8 +32,9 @@ def run_tool(
 
     In REPL mode the shared client is reused and never stopped.
     """
-    if ctx.connection:
-        request.setdefault("connectionName", ctx.connection)
+    conn_name = resolve_connection_name(ctx)
+    if conn_name:
+        request.setdefault("connectionName", conn_name)
 
     client = get_client(repl_mode=ctx.repl_mode)
     try:

src/pbi_cli/commands/dax.py

@@ -6,6 +6,7 @@ import sys
 
 import click
 
+from pbi_cli.commands._helpers import resolve_connection_name
 from pbi_cli.core.mcp_client import get_client
 from pbi_cli.core.output import format_mcp_result, print_error
 from pbi_cli.main import PbiContext, pass_context
@@ -59,8 +60,9 @@ def execute(
         "getExecutionMetrics": metrics or metrics_only,
         "executionMetricsOnly": metrics_only,
     }
-    if ctx.connection:
-        request["connectionName"] = ctx.connection
+    conn_name = resolve_connection_name(ctx)
+    if conn_name:
+        request["connectionName"] = conn_name
     if max_rows is not None:
         request["maxRows"] = max_rows
 
@@ -94,8 +96,9 @@ def validate(ctx: PbiContext, query: str, query_file: str | None, timeout: int)
         "query": resolved_query,
         "timeoutSeconds": timeout,
     }
-    if ctx.connection:
-        request["connectionName"] = ctx.connection
+    conn_name = resolve_connection_name(ctx)
+    if conn_name:
+        request["connectionName"] = conn_name
 
     client = get_client()
     try:
@@ -113,8 +116,9 @@ def validate(ctx: PbiContext, query: str, query_file: str | None, timeout: int)
 def clear_cache(ctx: PbiContext) -> None:
     """Clear the DAX query cache."""
     request: dict[str, object] = {"operation": "ClearCache"}
-    if ctx.connection:
-        request["connectionName"] = ctx.connection
+    conn_name = resolve_connection_name(ctx)
+    if conn_name:
+        request["connectionName"] = conn_name
 
     client = get_client()
     try:

tests/test_helpers.py

@@ -50,6 +50,13 @@ def test_run_tool_adds_connection(monkeypatch: pytest.MonkeyPatch) -> None:
 def test_run_tool_no_connection(monkeypatch: pytest.MonkeyPatch) -> None:
     mock = MockPbiMcpClient()
     monkeypatch.setattr("pbi_cli.commands._helpers.get_client", lambda repl_mode=False: mock)
+    # Ensure no last-used connection is found
+    from pbi_cli.core.connection_store import ConnectionStore
+
+    monkeypatch.setattr(
+        "pbi_cli.core.connection_store.load_connections",
+        lambda: ConnectionStore(),
+    )
 
     ctx = PbiContext(json_output=True)
     run_tool(ctx, "measure_operations", {"operation": "List"})