Feat(GRAPHQL): This PR allows updatable and nullable @id fields.

[JatinDev543]

Currently, @id fields are not updatable and also we enforce them to be non-null.
In this PR we are allowing @id fields to be updatable and nullable.

RFC:https://discuss.dgraph.io/t/rfc-mutable-and-null-able-id-field-in-graphql/13663
Related Posts:
https://discuss.dgraph.io/t/nullable-id-field/13296
https://discuss.dgraph.io/t/editable-id-fields/13295
https://discuss.dgraph.io/t/rfc-allow-multiple-unique-fields-in-graphql-schema/12008

---

This change is 

[pawanrawal]

Reviewed 29 of 29 files at r1.
Reviewable status: all files reviewed, 17 unresolved discussions (waiting on @jatindevdg)

---

graphql/e2e/auth/schema.graphql, line 855 at r1 (raw file):

) {
    company: String! @id
    company_Id: String @id

companyId

---

graphql/e2e/auth/schema.graphql, line 861 at r1 (raw file):

type Worker {
    reg_No: Int @id

regNo

---

graphql/e2e/auth/schema.graphql, line 862 at r1 (raw file):

type Worker {
    reg_No: Int @id
    UniqueID: Int @id

uniqueID

---

graphql/e2e/common/mutation.go, line 6499 at r1 (raw file):

                    }
                }`,
			error: "mutation updateEmployer failed because multiple nodes are selected in filter" +

failed because only one node is allowed in the filter while updating fields with @id directive

---

graphql/e2e/directives/schema.graphql, line 384 at r1 (raw file):

type Worker {
    name: String!
    reg_No: Int @id

regNo

---

graphql/e2e/directives/schema.graphql, line 385 at r1 (raw file):

    name: String!
    reg_No: Int @id
    UniqueID: Int @id

uniqueId

---

graphql/e2e/directives/schema.graphql, line 391 at r1 (raw file):

type Employer {
    company: String! @id
    company_Id: String @id

companyId

---

graphql/e2e/normal/schema.graphql, line 322 at r1 (raw file):

    name: String!
    reg_No: Int @id
    UniqueID: Int @id

uniqueId

---

graphql/e2e/normal/schema.graphql, line 323 at r1 (raw file):

    reg_No: Int @id
    UniqueID: Int @id
    emp_Id: String! @id

empId

---

graphql/e2e/normal/schema.graphql, line 328 at r1 (raw file):

type Employer {
    company: String! @id
    company_Id: String @id

companyId

---

graphql/resolve/mutation_rewriter.go, line 1815 at r1 (raw file):

					// In this case, as obj is the correct definition of the object, we update variableObjMap
					oldObj := xidMetadata.variableObjMap[variable]
					if len(oldObj) == 1 && len(obj) > 1 {

if there is a test case that was broken earlier, lets add that here. Otherwise lets keep it as it is

---

graphql/resolve/schema.graphql, line 396 at r1 (raw file):

    title: String @id
    ISBN: String @id
    BookId: Int @id

bookedId

---

graphql/resolve/update_mutation_test.yaml, line 1972 at r1 (raw file):

    	updateBook(input: $patch) {
    		book {
    			title

spacing seems a bit messed up

---

graphql/schema/gqlschema.go, line 1290 at r1 (raw file):

	if len(nonIDFields) == 0 {
		// The user might just have an predicate with reverse edge id field and nothing else.
		//We don't generate patch type in that case.

// We

---

graphql/schema/gqlschema_test.yml, line 633 at r1 (raw file):

    input: |
      type X {
        f1: Float! @id

this should remain?

---

graphql/schema/rules.go, line 2076 at r1 (raw file):

	dir *ast.Directive,
	secrets map[string]x.Sensitive) gqlerror.List {
	if field.Type.NamedType == "String" ||

Isn't this check applicable for non-nullable id fields as well?

---

graphql/schema/testdata/schemagen/output/custom-dql-query-with-subscription.graphql, line 439 at r1 (raw file):

input UserPatch {
	screen_name: String

screenName

[JatinDev543]

Reviewable status: 16 of 31 files reviewed, 17 unresolved discussions (waiting on @id, @jatindevdg, and @pawanrawal)

---

graphql/e2e/auth/schema.graphql, line 855 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

companyId

done.

---

graphql/e2e/auth/schema.graphql, line 861 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

regNo

done

---

graphql/e2e/auth/schema.graphql, line 862 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

uniqueID

changed.

---

graphql/e2e/common/mutation.go, line 6499 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

failed because only one node is allowed in the filter while updating fields with @id directive

changed.

---

graphql/e2e/directives/schema.graphql, line 384 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

regNo

done.

---

graphql/e2e/directives/schema.graphql, line 385 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

uniqueId

done.

---

graphql/e2e/directives/schema.graphql, line 391 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

companyId

done.

---

graphql/e2e/normal/schema.graphql, line 322 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

uniqueId

done.

---

graphql/e2e/normal/schema.graphql, line 323 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

empId

done.

---

graphql/e2e/normal/schema.graphql, line 328 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

companyId

done.

---

graphql/resolve/mutation_rewriter.go, line 1815 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

if there is a test case that was broken earlier, lets add that here. Otherwise lets keep it as it is

currently, it doesn't have any effect, because if we have more than one xid fields and we try to add reference in single mutation then that gives duplicate xid error. That itself is a bug. i have created ticket for it. we need to do some refactoring for this. There are couple of scenarios where duplicate xid error is not behaving correctly. while fixing that we can fix this also. Added TODO for this in code.

---

graphql/resolve/schema.graphql, line 396 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

bookedId

changed.

---

graphql/schema/gqlschema.go, line 1290 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

// We

changed.

---

graphql/schema/gqlschema_test.yml, line 633 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

this should remain?

added.

---

graphql/schema/rules.go, line 2076 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

Isn't this check applicable for non-nullable id fields as well?

Actually, NamedType, cover both nullable and non-nullable values.

---

graphql/schema/testdata/schemagen/output/custom-dql-query-with-subscription.graphql, line 439 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

screenName

changed.

[JatinDev543]

Reviewable status: 13 of 31 files reviewed, 17 unresolved discussions (waiting on @id and @pawanrawal)

---

graphql/resolve/update_mutation_test.yaml, line 1972 at r1 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

spacing seems a bit messed up

fixed.

[pawanrawal]

Reviewed 14 of 15 files at r2, 4 of 4 files at r3.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @jatindevdg)

---

graphql/resolve/mutation_rewriter.go, line 1832 at r3 (raw file):

					// In this case, as obj is the correct definition of the object, we update variableObjMap
					oldObj := xidMetadata.variableObjMap[variable]
					// TODO(GRAOHQL): This condition also needs to change in accordance with multiple xids.

TODO(jatin)

[JatinDev543]

Reviewable status: 29 of 31 files reviewed, 1 unresolved discussion (waiting on @pawanrawal)

---

graphql/resolve/mutation_rewriter.go, line 1832 at r3 (raw file):

Previously, pawanrawal (Pawan Rawal) wrote…

TODO(jatin)

changed