feat: create @requires integration that functions like a normal resol…

…ver (#3292)

* feat: create @requires integration that functions like a normal resolver

The "explicit_requires" flag current generates the @requires resolver inside the execution context. It also doesn't use the normal resolver resolution process and adds a custom implementation that is always called, even if the field isn't requested.

The new "computed_requires" flag looks for @requires directives and mutates the schema to add dynamic field arguments and directives that are used internally by gqlgen.

These additional directives (@entityReference and @populateFromRepresentations) are runtime directives that "computed_requires" adds implementations for that enable us to fetch the correct data from the representations array and populated it into the dynamic argument for the @requires field.

* Add mechanism for supporting statically provided directive implementations.

* Get @populateFromRepresentations working

* Add tests for computedrequires

* Update documentation

* Ensure everyone that should be is using version 2

* Fix linter issues

.golangci.yml

@@ -106,6 +106,10 @@ issues:
     - path: codegen/testserver/.*/resolver\.go
       linters:
         - gocritic
+    # The interfaces are autogenerated and don't conform to the paramTypeCombine rule
+    - path: _examples/federation/products/graph/entity.resolvers.go
+      linters:
+        - gocritic
     # Disable revive.use-any for backwards compatibility
     - path: graphql/map.go
       text: "use-any: since GO 1.18 'interface{}' can be replaced by 'any'"

_examples/federation/accounts/gqlgen.yml

@@ -9,6 +9,7 @@ exec:
 
 federation:
   filename: graph/federation.go
+  version: 2
   package: graph
 
 # Where should any generated models go?

_examples/federation/products/gqlgen.yml

@@ -9,6 +9,7 @@ exec:
 
 federation:
   filename: graph/federation.go
+  version: 2
   package: graph
 
 # Where should any generated models go?
@@ -66,3 +67,5 @@ models:
       - github.com/99designs/gqlgen/graphql.Int
       - github.com/99designs/gqlgen/graphql.Int64
       - github.com/99designs/gqlgen/graphql.Int32
+
+omit_complexity: true