Add JSON output for batch queries

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## Unreleased
 
+### Features
+
+- Add JSON output for batch queries with the `--json` option.
+
 ### Bug Fixes
 
 - Expand `~` in configured log file paths before opening the log.

litecli/main.py

@@ -16,7 +16,7 @@
 
 import click
 import sqlparse
-from cli_helpers.tabular_output import TabularOutputFormatter, preprocessors
+from cli_helpers.tabular_output import TabularOutputFormatter, json_output_adapter, preprocessors
 from prompt_toolkit.auto_suggest import AutoSuggestFromHistory
 from prompt_toolkit.completion import Completion, DynamicCompleter
 from prompt_toolkit.document import Document
@@ -67,6 +67,18 @@ def _load_sqlite3() -> Any:
 PACKAGE_ROOT = os.path.abspath(os.path.dirname(__file__))
 
 
+def _json_output_adapter(data: Iterable[Iterable[Any]], headers: Iterable[Any], **kwargs: Any) -> str:
+    rows = json_output_adapter.adapter(data, headers, **kwargs)
+    return "[{}]".format(",".join(rows))
+
+
+TabularOutputFormatter.register_new_formatter(
+    "json",
+    _json_output_adapter,
+    json_output_adapter.preprocessors,
+)
+
+
 class LiteCli(object):
     default_prompt = "\\d> "
     max_len_prompt = 45
@@ -931,6 +943,7 @@ def get_last_query(self) -> str | None:
 )
 @click.option("-t", "--table", is_flag=True, help="Display batch output in table format.")
 @click.option("--csv", is_flag=True, help="Display batch output in CSV format.")
+@click.option("--json", "json_output", is_flag=True, help="Display batch output in JSON format.")
 @click.option("--warn/--no-warn", default=None, help="Warn before running a destructive query.")
 @click.option("-e", "--execute", type=str, help="Execute command and quit.")
 @click.argument("database", default="", nargs=1)
@@ -942,6 +955,7 @@ def cli(
     auto_vertical_output: bool,
     table: bool,
     csv: bool,
+    json_output: bool,
     warn: bool | None,
     execute: str | None,
     liteclirc: str,
@@ -971,7 +985,9 @@ def cli(
     #  --execute argument
     if execute:
         try:
-            if csv:
+            if json_output:
+                litecli.formatter.format_name = "json"
+            elif csv:
                 litecli.formatter.format_name = "csv"
             elif not table:
                 litecli.formatter.format_name = "tsv"
@@ -998,7 +1014,9 @@ def cli(
         try:
             new_line = True
 
-            if csv:
+            if json_output:
+                litecli.formatter.format_name = "json"
+            elif csv:
                 litecli.formatter.format_name = "csv"
             elif not table:
                 litecli.formatter.format_name = "tsv"

tests/test_main.py

@@ -76,6 +76,14 @@ def test_execute_arg_with_csv(executor):
     assert expected in "".join(result.output)
 
 
+def test_execute_arg_with_json():
+    runner = CliRunner()
+    result = runner.invoke(cli, args=CLI_ARGS[:-1] + [":memory:", "-e", "select 'abc' as a;", "--json"])
+
+    assert result.exit_code == 0
+    assert '[{"a":"abc"}]' in result.output
+
+
 @dbtest
 def test_batch_mode(executor):
     run(executor, """create table test(a text)""")
@@ -134,6 +142,14 @@ def test_batch_mode_csv(executor):
     assert expected in "".join(result.output)
 
 
+def test_batch_mode_json():
+    runner = CliRunner()
+    result = runner.invoke(cli, args=CLI_ARGS[:-1] + [":memory:", "--json"], input="select 'abc' as a;")
+
+    assert result.exit_code == 0
+    assert '[{"a":"abc"}]' in result.output
+
+
 def test_help_strings_end_with_periods():
     """Make sure click options have help text that end with a period."""
     for param in cli.params: