fix(GraphQL): fix bug in custom resolver, now body need not have all the fields.

[JatinDev543]

This PR fix bug in custom resolver, now body need not have all the fields(both nullable and non-nullable).

https://discuss.dgraph.io/t/evaluation-of-custom-field-failed-while-substituting-variables-into-body-for-remote-endpoint-with-an-error/8700

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This change is 

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[arijitAD]

Reviewable status: 0 of 2 files reviewed, 3 unresolved discussions (waiting on @jatindevdg, @MichaelJCompton, and @pawanrawal)

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graphql/schema/wrappers.go, line 1850 at r1 (raw file):

	val, ok := variables[key[1:]]
	if !ok {
		return nil, nil, ok

Can you do nil, nil, false? It will be clearer when we are reading the code.
and val, nil, true below
Also, can you check what is the default value returned by map for interface{} if the element is not present?
If it's nil then you can just have a single line. return val, nil, ok

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graphql/schema/wrappers.go, line 1877 at r1 (raw file):

			if ok {
				object[k] = vval

Extra line

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graphql/schema/wrappers_test.go, line 427 at r1 (raw file):

		},
		{
			"skip variable that is not  present and shouldn't return error ",

Extra space. Probably rename it to "Skip missing variable in the HTTP body"

[JatinDev543]

Reviewable status: 0 of 2 files reviewed, 3 unresolved discussions (waiting on @arijitAD, @MichaelJCompton, and @pawanrawal)

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graphql/schema/wrappers.go, line 1850 at r1 (raw file):

Previously, arijitAD (Arijit Das) wrote…

Can you do nil, nil, false? It will be clearer when we are reading the code.
and val, nil, true below
Also, can you check what is the default value returned by map for interface{} if the element is not present?
If it's nil then you can just have a single line. return val, nil, ok

yeah we map return nil for interface{} if element not present. Changed to return val, nil, ok.

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graphql/schema/wrappers.go, line 1877 at r1 (raw file):

Previously, arijitAD (Arijit Das) wrote…

Extra line

removed.

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graphql/schema/wrappers_test.go, line 427 at r1 (raw file):

Previously, arijitAD (Arijit Das) wrote…

Extra space. Probably rename it to "Skip missing variable in the HTTP body"

renamed.

[pawanrawal]

Reviewable status: 0 of 2 files reviewed, 4 unresolved discussions (waiting on @arijitAD, @jatindevdg, @MichaelJCompton, and @pawanrawal)

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graphql/schema/wrappers_test.go, line 430 at r2 (raw file):

			map[string]interface{}{"postID": "0x9"},
			map[string]interface{}{"author": "$id", "post": map[string]interface{}{"id": "$postID"}},
			map[string]interface{}{"author": "$id", "post": map[string]interface{}{"id": "0x9"}},

Doesn't look like it was skipped though. The expected map should not have had the "author": "$id" key value pair.

[MichaelJCompton]

It does look like the test isn't quite right. What I expect is that if the author's id is missing in the variables, then "author" shouldn't get serialized into the result body at all.

[JatinDev543]

Reviewable status: 0 of 4 files reviewed, 4 unresolved discussions (waiting on @arijitAD, @MichaelJCompton, and @pawanrawal)

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graphql/schema/wrappers_test.go, line 430 at r2 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

Doesn't look like it was skipped though. The expected map should not have had the "author": "$id" key value pair.

fixed it.

[JatinDev543]

It does look like the test isn't quite right. What I expect is that if the author's id is missing in the variables, then "author" shouldn't get serialized into the result body at all.

fixed it.

[pawanrawal]

Can you verify that optional arguments in custom query/mutation are either sent as null when supplied null or not sent if they are not given?

Reviewed 4 of 4 files at r3.
Reviewable status: all files reviewed, 5 unresolved discussions (waiting on @arijitAD, @jatindevdg, and @MichaelJCompton)

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graphql/e2e/custom_logic/custom_logic_test.go, line 1023 at r3 (raw file):

			@custom(
				http: {
					url: "http://mock:8888/userName"

Add a new endpoint to the mock server called /userNameWithoutAddress. In that verify that the body should not contain address.

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graphql/schema/wrappers.go, line 1899 at r3 (raw file):

				return err
			}
			//if ok {

Remove this

[JatinDev543]

Can you verify that optional arguments in custom query/mutation are either sent as null when supplied null or not sent if they are not given?

Reviewed 4 of 4 files at r3.
Reviewable status: all files reviewed, 5 unresolved discussions (waiting on @arijitAD, @jatindevdg, and @MichaelJCompton)

graphql/e2e/custom_logic/custom_logic_test.go, line 1023 at r3 (raw file):

			@custom(
				http: {
					url: "http://mock:8888/userName"

Add a new endpoint to the mock server called /userNameWithoutAddress. In that verify that the body should not contain address.

added test.

graphql/schema/wrappers.go, line 1899 at r3 (raw file):

				return err
			}
			//if ok {

Remove this

removed.

[pawanrawal]

is master merged into this branch? CI seems to be failing

Reviewed 3 of 3 files at r4.
Reviewable status: all files reviewed, 6 unresolved discussions (waiting on @arijitAD, @jatindevdg, @MichaelJCompton, and @pawanrawal)

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graphql/e2e/custom_logic/cmd/main.go, line 1213 at r4 (raw file):

	http.HandleFunc("/favMovies/", getFavMoviesHandler)
	http.HandleFunc("/favMoviesPost/", postFavMoviesHandler)
	http.HandleFunc("/favMoviesPostWithBody/", PostFavMoviesWithBodyHandler)

This doesn't have to start with capital P.