Support --queryStringParameters parameter when generating api gateway aws-proxy event

[lvthillo]

Describe your idea/feature/enhancement

I want to generate an API GW event to test my lambda locally. My lambda expects queryStringParameters.

I tried: sam local generate-event apigateway aws-proxy --method GET --path document --body "" --queryStringParameters "{"documentId": "1044", "versionId": "v_1"}"

Error: no such option: --queryStringParameters

Proposal

It's not clear how I can generate an event with custom queryStringParameters. I don't want to edit the json manually if possible.

It would be nice to have some thing like the parameter --queryStringParameters to make it easy to generate queryStringParameters inside the event.json

[jfuss]

@lvthillo Right now, we don't have a better way than generating the event and then editing the output to add the query parameters. This should be something simple to add, would you be interested in contributing it?

[lvthillo]

@jfuss I was checking in the code base and I don't know if it's really simple. This is samcli/lib/generated_sample_events/events/apigateway/AwsProxy.json

{
  "body": "{{{body}}}",
  "resource": "{{{resource}}}",
  "path": "/{{{path}}}",
  "httpMethod": "{{{method}}}",
  "isBase64Encoded": true,
  "queryStringParameters": {
    "foo": "bar"
  },
  ...

As you can see the queryStringParameters value is of type dict and not a string like all the others. So if I understand correctly I can not just update the samcli/lib/generated_sample_events/event-mapping.json and just add:

        "querystringparameters": {
          "type": "string",
          "default": "{"foo": "bar"}"
        },

It should be something like (dict and without quotes):

        "querystringparameters": {
          "type": "dict",
          "default": {"foo": "bar"}
        },

The output:

samdev local generate-event apigateway aws-proxy --method GET --path document --body "hello"
{'method': 'GET', 'path': 'document', 'body': 'aGVsbG8=', 'stage': 'prod', 'querystringparameters': {'test': 'body'}, 'resource': '/{proxy+}', 'account_id': '123456789012', 'dns_suffix': 'us-east-1.amazonaws.com'}

But here it's substituted as a string

{
  "body": "aGVsbG8=",
  "resource": "/{proxy+}",
  "path": "/document",
  "httpMethod": "GET",
  "isBase64Encoded": true,
  "queryStringParameters": "{'test': 'body'}",
  "multiValueQueryStringParameters": {
    "foo": [
      "bar"
    ]
  },

The 'issue' seems to occur here:

        # open the file
        with open(file_path) as f:
            data = json.load(f)

        data = json.dumps(data, indent=2)
        
        # return the substituted file
        return renderer.render(data, values_to_sub)

We're passing in the data as JSON but "{"key":"value"}" is a string and not a dict. A (probably not so good) idea could be to check if there are dicts in the values_to_sub and for each dict replace the json loaded "{"key":"value"}" with {"key":"value"}

Example:

import chevron
import json

def convert_dicts(data):
    updated_data = data
    for key, value in values_to_sub.items():
        if type(value) is dict:
            substitution = "{{{%s}}}" % key
            updated_data = updated_data.replace('"%s"' % substitution, substitution)
    return updated_data

if __name__== "__main__":
    values_to_sub = {'method': 'GET', 'path': 'document', 'body': 'aGVsbG8=', 'stage': 'prod', 'querystringparameters': {'test': 'body'}, 'resource': '/{proxy+}', 'test': {'test': 'jo'}}

    data = '''
    {
    "body": "{{{body}}}",
    "resource": "{{{resource}}}",
    "path": "/{{{path}}}",
    "httpMethod": "{{{method}}}",
    "isBase64Encoded": true,
    "queryStringParameters": "{{{querystringparameters}}}",
    "multiValueQueryStringParameters": {
        "foo": [
        "bar"
        ]
    },
    "test": "{{{test}}}"
    }
    '''

    output = convert_dicts(data)
    test = chevron.render(output, values_to_sub)
    print(test)

output:

    {
    "body": "aGVsbG8=",
    "resource": "/{proxy+}",
    "path": "/document",
    "httpMethod": "GET",
    "isBase64Encoded": true,
    "queryStringParameters": {'test': 'body'},
    "multiValueQueryStringParameters": {
        "foo": [
        "bar"
        ]
    },
    "test": {'test': 'jo'}
    }