fix(zed): make the db up/down [N] tasks work under fish (#15925)

.zed/alembic_step.py

@@ -0,0 +1,53 @@
+"""Prompt for N, then move the schema up or down by N alembic revisions.
+
+An empty answer goes all the way: `head` for up, `base` for down.
+
+Zed joins task `args` into one command line for the user's shell without
+quoting, so the prompt lives here rather than in shell syntax that only some
+shells (sh, bash) accept.
+
+Usage:
+    alembic_step.py (up | down)
+"""
+
+from __future__ import annotations
+
+import runpy
+import sys
+from pathlib import Path
+
+ZED_DIR = Path(__file__).resolve().parent
+
+DIRECTIONS = {
+    "up": ("upgrade", "head", "+"),
+    "down": ("downgrade", "base", "-"),
+}
+
+
+def main() -> None:
+    if len(sys.argv) != 2 or sys.argv[1] not in DIRECTIONS:
+        raise SystemExit(f"usage: {Path(sys.argv[0]).name} (up | down)")
+
+    command, default, sign = DIRECTIONS[sys.argv[1]]
+    answer = input(f"Revisions to {command} (empty = {default}): ").strip()
+    if not answer:
+        revision = default
+    elif answer.isdigit() and int(answer) > 0:
+        revision = f"{sign}{int(answer)}"
+    else:
+        raise SystemExit(f"expected a positive whole number, got {answer!r}")
+
+    launcher = ZED_DIR / "dotenv_launch.py"
+    sys.argv = [
+        str(launcher),
+        ".vscode/.env",
+        "--module",
+        "alembic",
+        command,
+        revision,
+    ]
+    runpy.run_path(str(launcher), run_name="__main__")
+
+
+if __name__ == "__main__":
+    main()

.zed/tasks.json

@@ -113,15 +113,13 @@
   // --- 5. Database ---
   {
     "label": "db: up [N]",
-    "command": "sh",
-    "args": ["-c", "printf 'Revisions to upgrade (empty = head): '; read n; if [ -z \"$n\" ]; then rev=head; else rev=\"+$n\"; fi; exec \"$ZED_WORKTREE_ROOT/.venv/bin/python\" -m dotenv -f \"$ZED_WORKTREE_ROOT/.vscode/.env\" run -- \"$ZED_WORKTREE_ROOT/.venv/bin/python\" -m alembic upgrade \"$rev\""],
+    "command": "\"$ZED_WORKTREE_ROOT/.venv/bin/python\" \"$ZED_WORKTREE_ROOT/.zed/alembic_step.py\" up",
     "cwd": "$ZED_WORKTREE_ROOT/backend",
     "use_new_terminal": true,
   },
   {
     "label": "db: down [N]",
-    "command": "sh",
-    "args": ["-c", "printf 'Revisions to downgrade (empty = base): '; read n; if [ -z \"$n\" ]; then rev=base; else rev=\"-$n\"; fi; exec \"$ZED_WORKTREE_ROOT/.venv/bin/python\" -m dotenv -f \"$ZED_WORKTREE_ROOT/.vscode/.env\" run -- \"$ZED_WORKTREE_ROOT/.venv/bin/python\" -m alembic downgrade \"$rev\""],
+    "command": "\"$ZED_WORKTREE_ROOT/.venv/bin/python\" \"$ZED_WORKTREE_ROOT/.zed/alembic_step.py\" down",
     "cwd": "$ZED_WORKTREE_ROOT/backend",
     "use_new_terminal": true,
   },