Detect TTY, Go Into Non-Interactive Mode If Not TTY (#186)

* Detect TTY, Go Into Non-Interactive Mode If Not TTY

The selection prompt breaks when not in a terminal emulator / pseudo tty.

This checks for a tty and reverts to the old non-interactive behavior if not running in a tty.

* Fix tests

* Bump to v0.6.6

newrelic_lambda_cli/layers.py

@@ -1,4 +1,6 @@
 # -*- coding: utf-8 -*-
+#
+import sys  #
 
 import botocore
 import click
@@ -44,16 +46,25 @@ def index(region, runtime, architecture):
 def layer_selection(available_layers, runtime, architecture):
     selected_layer = []
     if len(available_layers) > 1:
-        layerOptions = []
-        for layer in available_layers:
-            layerOptions.append(layer["LatestMatchingVersion"]["LayerVersionArn"])
-
-        response = enquiries.choose(
-            "Discovered layers for runtime %s (%s)" % (runtime, architecture),
-            layerOptions,
-        )
-        success("Layer %s selected" % response)
-        selected_layer.append(response)
+        layer_options = [
+            layer["LatestMatchingVersion"]["LayerVersionArn"]
+            for layer in available_layers
+        ]
+
+        if sys.stdout.isatty():
+            response = enquiries.choose(
+                "Discovered multiple layers for runtime %s (%s)"
+                % (runtime, architecture),
+                layer_options,
+            )
+            success("Layer %s selected" % response)
+            selected_layer.append(response)
+        else:
+            raise click.UsageError(
+                "Discovered multiple layers for runtime %s (%s):\n%s\n"
+                "Pass --layer-arn to specify a layer ARN"
+                % (runtime, architecture, "\n".join(layer_options))
+            )
     else:
         selected_layer.append(
             available_layers[0]["LatestMatchingVersion"]["LayerVersionArn"]

setup.py

@@ -6,7 +6,7 @@
 
 setup(
     name="newrelic-lambda-cli",
-    version="0.6.5",
+    version="0.6.6",
     python_requires=">=3.3",
     description="A CLI to install the New Relic AWS Lambda integration and layers.",
     long_description=README,

tests/test_layers.py

@@ -171,26 +171,35 @@ def test_add_new_relic(aws_credentials, mock_function_config):
                 in update_kwargs["Environment"]["Variables"]["NEW_RELIC_LAMBDA_HANDLER"]
             )
 
-    with patch("newrelic_lambda_cli.layers.enquiries.choose") as mock_enquiries:
-        mock_layers = [
-            {
-                "LatestMatchingVersion": {
-                    "LayerVersionArn": "arn:aws:lambda:us-east-1:123456789:layer/javajava"
-                }
-            },
-            {
-                "LatestMatchingVersion": {
-                    "LayerVersionArn": "arn:aws:lambda:us-east-1:123456789:layer/NewRelicLambdaExtension"
-                }
-            },
-        ]
+    mock_layers = [
+        {
+            "LatestMatchingVersion": {
+                "LayerVersionArn": "arn:aws:lambda:us-east-1:123456789:layer/javajava"
+            }
+        },
+        {
+            "LatestMatchingVersion": {
+                "LayerVersionArn": "arn:aws:lambda:us-east-1:123456789:layer/NewRelicLambdaExtension"
+            }
+        },
+    ]
+
+    with patch("newrelic_lambda_cli.layers.enquiries.choose") as mock_enquiries, patch(
+        "sys.stdout.isatty"
+    ) as mock_isatty:
+        mock_isatty.return_value = True
         mock_enquiries.return_value = (
             "arn:aws:lambda:us-east-1:123456789:layer/javajava"
         )
 
         result = layer_selection(mock_layers, "python3.7", "x86_64")
         assert result == [mock_enquiries.return_value]
 
+    with patch("sys.stdout.isatty") as mock_isatty:
+        mock_isatty.return_value = False
+        with pytest.raises(UsageError):
+            layer_selection(mock_layers, "python3.7", "x86_64")
+
     config = mock_function_config("python3.7")
     _add_new_relic(
         layer_install(