Sort operations to guarantee a stable order (#156)

Problem: currently when using a wildcard that covers multiple files in `operations:` YAML directive the generator emits functions in a non-stable ordering due to the use of map for storing file names:

https://github.com/Khan/genqlient/blob/e0accbded177db9143314911bacedf61b2cda656/generate/parse.go#L68-L84

Solution: sort the operations before emitting them.

internal/integration/server/gqlgen_exec.go

@@ -1560,6 +1560,41 @@ func (ec *executionContext) ___Directive_args(ctx context.Context, field graphql
 	return ec.marshalN__InputValue2ᚕgithubᚗcomᚋ99designsᚋgqlgenᚋgraphqlᚋintrospectionᚐInputValueᚄ(ctx, field.Selections, res)
 }
 
+func (ec *executionContext) ___Directive_isRepeatable(ctx context.Context, field graphql.CollectedField, obj *introspection.Directive) (ret graphql.Marshaler) {
+	defer func() {
+		if r := recover(); r != nil {
+			ec.Error(ctx, ec.Recover(ctx, r))
+			ret = graphql.Null
+		}
+	}()
+	fc := &graphql.FieldContext{
+		Object:     "__Directive",
+		Field:      field,
+		Args:       nil,
+		IsMethod:   false,
+		IsResolver: false,
+	}
+
+	ctx = graphql.WithFieldContext(ctx, fc)
+	resTmp, err := ec.ResolverMiddleware(ctx, func(rctx context.Context) (interface{}, error) {
+		ctx = rctx // use context from middleware stack in children
+		return obj.IsRepeatable, nil
+	})
+	if err != nil {
+		ec.Error(ctx, err)
+		return graphql.Null
+	}
+	if resTmp == nil {
+		if !graphql.HasFieldError(ctx, fc) {
+			ec.Errorf(ctx, "must not be null")
+		}
+		return graphql.Null
+	}
+	res := resTmp.(bool)
+	fc.Result = res
+	return ec.marshalNBoolean2bool(ctx, field.Selections, res)
+}
+
 func (ec *executionContext) ___EnumValue_name(ctx context.Context, field graphql.CollectedField, obj *introspection.EnumValue) (ret graphql.Marshaler) {
 	defer func() {
 		if r := recover(); r != nil {
@@ -2858,6 +2893,11 @@ func (ec *executionContext) ___Directive(ctx context.Context, sel ast.SelectionS
 			if out.Values[i] == graphql.Null {
 				invalids++
 			}
+		case "isRepeatable":
+			out.Values[i] = ec.___Directive_isRepeatable(ctx, field, obj)
+			if out.Values[i] == graphql.Null {
+				invalids++
+			}
 		default:
 			panic("unknown field " + strconv.Quote(field.Name))
 		}
@@ -3109,6 +3149,7 @@ func (ec *executionContext) marshalNBeing2ᚕgithubᚗcomᚋKhanᚋgenqlientᚋi
 
 	}
 	wg.Wait()
+
 	return ret
 }
 
@@ -3169,6 +3210,12 @@ func (ec *executionContext) marshalNDate2ᚕstringᚄ(ctx context.Context, sel a
 		ret[i] = ec.marshalNDate2string(ctx, sel, v[i])
 	}
 
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3214,6 +3261,12 @@ func (ec *executionContext) marshalNID2ᚕstringᚄ(ctx context.Context, sel ast
 		ret[i] = ec.marshalNID2string(ctx, sel, v[i])
 	}
 
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3291,6 +3344,13 @@ func (ec *executionContext) marshalNUser2ᚕᚖgithubᚗcomᚋKhanᚋgenqlient
 
 	}
 	wg.Wait()
+
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3342,6 +3402,13 @@ func (ec *executionContext) marshalN__Directive2ᚕgithubᚗcomᚋ99designsᚋgq
 
 	}
 	wg.Wait()
+
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3415,6 +3482,13 @@ func (ec *executionContext) marshalN__DirectiveLocation2ᚕstringᚄ(ctx context
 
 	}
 	wg.Wait()
+
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3464,6 +3538,13 @@ func (ec *executionContext) marshalN__InputValue2ᚕgithubᚗcomᚋ99designsᚋg
 
 	}
 	wg.Wait()
+
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3505,6 +3586,13 @@ func (ec *executionContext) marshalN__Type2ᚕgithubᚗcomᚋ99designsᚋgqlgen
 
 	}
 	wg.Wait()
+
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3691,6 +3779,7 @@ func (ec *executionContext) marshalOUser2ᚕᚖgithubᚗcomᚋKhanᚋgenqlient
 
 	}
 	wg.Wait()
+
 	return ret
 }
 
@@ -3738,6 +3827,13 @@ func (ec *executionContext) marshalO__EnumValue2ᚕgithubᚗcomᚋ99designsᚋgq
 
 	}
 	wg.Wait()
+
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3778,6 +3874,13 @@ func (ec *executionContext) marshalO__Field2ᚕgithubᚗcomᚋ99designsᚋgqlgen
 
 	}
 	wg.Wait()
+
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3818,6 +3921,13 @@ func (ec *executionContext) marshalO__InputValue2ᚕgithubᚗcomᚋ99designsᚋg
 
 	}
 	wg.Wait()
+
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }
 
@@ -3865,6 +3975,13 @@ func (ec *executionContext) marshalO__Type2ᚕgithubᚗcomᚋ99designsᚋgqlgen
 
 	}
 	wg.Wait()
+
+	for _, e := range ret {
+		if e == graphql.Null {
+			return graphql.Null
+		}
+	}
+
 	return ret
 }