all: Add support for unknown value refinement data to all types

attr/value.go

@@ -6,6 +6,7 @@ package attr
 import (
 	"context"
 
+	"github.com/hashicorp/terraform-plugin-framework/types/refinement"
 	"github.com/hashicorp/terraform-plugin-go/tftypes"
 )
 
@@ -69,3 +70,17 @@ type Value interface {
 	// compatibility guarantees within the framework.
 	String() string
 }
+
+// ValueWithNotNullRefinement defines an interface describing a Value that can contain
+// a refinement that indicates the Value is unknown, but will not be null once it becomes known.
+//
+// This interface is implemented by all base value types except for DynamicValue, as dynamic types
+// in Terraform don't support value refinements.
+type ValueWithNotNullRefinement interface {
+	Value
+
+	// NotNullRefinement returns value refinement data and a boolean indicating if a NotNull refinement
+	// exists on the given Value. If a Value contains a NotNull refinement, this indicates that the value
+	// is unknown, but the eventual known value will not be null.
+	NotNullRefinement() (*refinement.NotNull, bool)
+}

go.mod

@@ -6,7 +6,7 @@ toolchain go1.22.7
 
 require (
 	github.com/google/go-cmp v0.6.0
-	github.com/hashicorp/terraform-plugin-go v0.25.0
+	github.com/hashicorp/terraform-plugin-go v0.25.1-0.20250116190359-f977ddce3f6c
 	github.com/hashicorp/terraform-plugin-log v0.9.0
 )
 
@@ -16,7 +16,7 @@ require (
 	github.com/hashicorp/go-hclog v1.5.0 // indirect
 	github.com/hashicorp/go-plugin v1.6.2 // indirect
 	github.com/hashicorp/go-uuid v1.0.3 // indirect
-	github.com/hashicorp/terraform-registry-address v0.2.3 // indirect
+	github.com/hashicorp/terraform-registry-address v0.2.4 // indirect
 	github.com/hashicorp/terraform-svchost v0.1.1 // indirect
 	github.com/hashicorp/yamux v0.1.1 // indirect
 	github.com/mattn/go-colorable v0.1.12 // indirect
@@ -25,10 +25,10 @@ require (
 	github.com/oklog/run v1.0.0 // indirect
 	github.com/vmihailenco/msgpack/v5 v5.4.1 // indirect
 	github.com/vmihailenco/tagparser/v2 v2.0.0 // indirect
-	golang.org/x/net v0.28.0 // indirect
-	golang.org/x/sys v0.24.0 // indirect
-	golang.org/x/text v0.17.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20240814211410-ddb44dafa142 // indirect
-	google.golang.org/grpc v1.67.1 // indirect
-	google.golang.org/protobuf v1.35.1 // indirect
+	golang.org/x/net v0.34.0 // indirect
+	golang.org/x/sys v0.29.0 // indirect
+	golang.org/x/text v0.21.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20241015192408-796eee8c2d53 // indirect
+	google.golang.org/grpc v1.69.4 // indirect
+	google.golang.org/protobuf v1.36.3 // indirect
 )

go.sum

@@ -5,22 +5,28 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fatih/color v1.13.0 h1:8LOYc1KYPPmyKMuN8QV2DNRWNbLo6LZ0iLs8+mlH53w=
 github.com/fatih/color v1.13.0/go.mod h1:kLAiJbzzSOZDVNGyDpeOxJ47H46qBXwg5ILebYFFOfk=
+github.com/go-logr/logr v1.4.2 h1:6pFjapn8bFcIbiKo3XT4j/BhANplGihG6tvd+8rYgrY=
+github.com/go-logr/logr v1.4.2/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/hashicorp/go-hclog v1.5.0 h1:bI2ocEMgcVlz55Oj1xZNBsVi900c7II+fWDyV9o+13c=
 github.com/hashicorp/go-hclog v1.5.0/go.mod h1:W4Qnvbt70Wk/zYJryRzDRU/4r0kIg0PVHBcfoyhpF5M=
 github.com/hashicorp/go-plugin v1.6.2 h1:zdGAEd0V1lCaU0u+MxWQhtSDQmahpkwOun8U8EiRVog=
 github.com/hashicorp/go-plugin v1.6.2/go.mod h1:CkgLQ5CZqNmdL9U9JzM532t8ZiYQ35+pj3b1FD37R0Q=
 github.com/hashicorp/go-uuid v1.0.3 h1:2gKiV6YVmrJ1i2CKKa9obLvRieoRGviZFL26PcT/Co8=
 github.com/hashicorp/go-uuid v1.0.3/go.mod h1:6SBZvOh/SIDV7/2o3Jml5SYk/TvGqwFJ/bN7x4byOro=
-github.com/hashicorp/terraform-plugin-go v0.25.0 h1:oi13cx7xXA6QciMcpcFi/rwA974rdTxjqEhXJjbAyks=
-github.com/hashicorp/terraform-plugin-go v0.25.0/go.mod h1:+SYagMYadJP86Kvn+TGeV+ofr/R3g4/If0O5sO96MVw=
+github.com/hashicorp/terraform-plugin-go v0.25.1-0.20250116190359-f977ddce3f6c h1:jRBaf696GIfT5LT+ZflOQUWI6MNEdntXFp6YO11ACUU=
+github.com/hashicorp/terraform-plugin-go v0.25.1-0.20250116190359-f977ddce3f6c/go.mod h1:+CXjuLDiFgqR+GcrM5a2E2Kal5t5q2jb0E3D57tTdNY=
 github.com/hashicorp/terraform-plugin-log v0.9.0 h1:i7hOA+vdAItN1/7UrfBqBwvYPQ9TFvymaRGZED3FCV0=
 github.com/hashicorp/terraform-plugin-log v0.9.0/go.mod h1:rKL8egZQ/eXSyDqzLUuwUYLVdlYeamldAHSxjUFADow=
-github.com/hashicorp/terraform-registry-address v0.2.3 h1:2TAiKJ1A3MAkZlH1YI/aTVcLZRu7JseiXNRHbOAyoTI=
-github.com/hashicorp/terraform-registry-address v0.2.3/go.mod h1:lFHA76T8jfQteVfT7caREqguFrW3c4MFSPhZB7HHgUM=
+github.com/hashicorp/terraform-registry-address v0.2.4 h1:JXu/zHB2Ymg/TGVCRu10XqNa4Sh2bWcqCNyKWjnCPJA=
+github.com/hashicorp/terraform-registry-address v0.2.4/go.mod h1:tUNYTVyCtU4OIGXXMDp7WNcJ+0W1B4nmstVDgHMjfAU=
 github.com/hashicorp/terraform-svchost v0.1.1 h1:EZZimZ1GxdqFRinZ1tpJwVxxt49xc/S52uzrw4x0jKQ=
 github.com/hashicorp/terraform-svchost v0.1.1/go.mod h1:mNsjQfZyf/Jhz35v6/0LWcv26+X7JPS+buii2c9/ctc=
 github.com/hashicorp/yamux v0.1.1 h1:yrQxtgseBDrq9Y652vSRDvsKCJKOUD+GzTS4Y0Y8pvE=
@@ -48,24 +54,34 @@ github.com/vmihailenco/msgpack/v5 v5.4.1 h1:cQriyiUvjTwOHg8QZaPihLWeRAAVoCpE00IU
 github.com/vmihailenco/msgpack/v5 v5.4.1/go.mod h1:GaZTsDaehaPpQVyxrf5mtQlH+pc21PIudVV/E3rRQok=
 github.com/vmihailenco/tagparser/v2 v2.0.0 h1:y09buUbR+b5aycVFQs/g70pqKVZNBmxwAhO7/IwNM9g=
 github.com/vmihailenco/tagparser/v2 v2.0.0/go.mod h1:Wri+At7QHww0WTrCBeu4J6bNtoV6mEfg5OIWRZA9qds=
-golang.org/x/net v0.28.0 h1:a9JDOJc5GMUJ0+UDqmLT86WiEy7iWyIhz8gz8E4e5hE=
-golang.org/x/net v0.28.0/go.mod h1:yqtgsTWOOnlGLG9GFRrK3++bGOUEkNBoHZc8MEDWPNg=
+go.opentelemetry.io/otel v1.31.0 h1:NsJcKPIW0D0H3NgzPDHmo0WW6SptzPdqg/L1zsIm2hY=
+go.opentelemetry.io/otel v1.31.0/go.mod h1:O0C14Yl9FgkjqcCZAsE053C13OaddMYr/hz6clDkEJE=
+go.opentelemetry.io/otel/metric v1.31.0 h1:FSErL0ATQAmYHUIzSezZibnyVlft1ybhy4ozRPcF2fE=
+go.opentelemetry.io/otel/metric v1.31.0/go.mod h1:C3dEloVbLuYoX41KpmAhOqNriGbA+qqH6PQ5E5mUfnY=
+go.opentelemetry.io/otel/sdk v1.31.0 h1:xLY3abVHYZ5HSfOg3l2E5LUj2Cwva5Y7yGxnSW9H5Gk=
+go.opentelemetry.io/otel/sdk v1.31.0/go.mod h1:TfRbMdhvxIIr/B2N2LQW2S5v9m3gOQ/08KsbbO5BPT0=
+go.opentelemetry.io/otel/sdk/metric v1.31.0 h1:i9hxxLJF/9kkvfHppyLL55aW7iIJz4JjxTeYusH7zMc=
+go.opentelemetry.io/otel/sdk/metric v1.31.0/go.mod h1:CRInTMVvNhUKgSAMbKyTMxqOBC0zgyxzW55lZzX43Y8=
+go.opentelemetry.io/otel/trace v1.31.0 h1:ffjsj1aRouKewfr85U2aGagJ46+MvodynlQ1HYdmJys=
+go.opentelemetry.io/otel/trace v1.31.0/go.mod h1:TXZkRk7SM2ZQLtR6eoAWQFIHPvzQ06FJAsO1tJg480A=
+golang.org/x/net v0.34.0 h1:Mb7Mrk043xzHgnRM88suvJFwzVrRfHEHJEl5/71CKw0=
+golang.org/x/net v0.34.0/go.mod h1:di0qlW3YNM5oh6GqDGQr92MyTozJPmybPK4Ev/Gm31k=
 golang.org/x/sys v0.0.0-20200116001909-b77594299b42/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220503163025-988cb79eb6c6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.24.0 h1:Twjiwq9dn6R1fQcyiK+wQyHWfaz/BJB+YIpzU/Cv3Xg=
-golang.org/x/sys v0.24.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.17.0 h1:XtiM5bkSOt+ewxlOE/aE/AKEHibwj/6gvWMl9Rsh0Qc=
-golang.org/x/text v0.17.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20240814211410-ddb44dafa142 h1:e7S5W7MGGLaSu8j3YjdezkZ+m1/Nm0uRVRMEMGk26Xs=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20240814211410-ddb44dafa142/go.mod h1:UqMtugtsSgubUsoxbuAoiCXvqvErP7Gf0so0mK9tHxU=
-google.golang.org/grpc v1.67.1 h1:zWnc1Vrcno+lHZCOofnIMvycFcc0QRGIzm9dhnDX68E=
-google.golang.org/grpc v1.67.1/go.mod h1:1gLDyUQU7CTLJI90u3nXZ9ekeghjeM7pTDZlqFNg2AA=
-google.golang.org/protobuf v1.35.1 h1:m3LfL6/Ca+fqnjnlqQXNpFPABW1UD7mjh8KO2mKFytA=
-google.golang.org/protobuf v1.35.1/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
+golang.org/x/sys v0.29.0 h1:TPYlXGxvx1MGTn2GiZDhnjPA9wZzZeGKHHmKhHYvgaU=
+golang.org/x/sys v0.29.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
+golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20241015192408-796eee8c2d53 h1:X58yt85/IXCx0Y3ZwN6sEIKZzQtDEYaBWrDvErdXrRE=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20241015192408-796eee8c2d53/go.mod h1:GX3210XPVPUjJbTUbvwI8f2IpZDMZuPJWDzDuebbviI=
+google.golang.org/grpc v1.69.4 h1:MF5TftSMkd8GLw/m0KM6V8CMOCY6NZ1NQDPGFgbTt4A=
+google.golang.org/grpc v1.69.4/go.mod h1:vyjdE6jLBI76dgpDojsFGNaHlxdjXN9ghpnd2o7JGZ4=
+google.golang.org/protobuf v1.36.3 h1:82DV7MYdb8anAVi3qge1wSnMDrnKK7ebr+I0hHRN1BU=
+google.golang.org/protobuf v1.36.3/go.mod h1:9fA7Ob0pmnwhb644+1+CVWFRbNajQ6iRojtC/QF5bRE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/fwserver/attribute_validation.go

@@ -19,7 +19,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-framework/types/basetypes"
 )
 
-// ValidateAttributeRequest repesents a request for attribute validation.
+// ValidateAttributeRequest represents a request for attribute validation.
 type ValidateAttributeRequest struct {
 	// AttributePath contains the path of the attribute. Use this path for any
 	// response diagnostics.
@@ -137,33 +137,48 @@ func AttributeValidate(ctx context.Context, a fwschema.Attribute, req ValidateAt
 
 	AttributeValidateNestedAttributes(ctx, a, req, resp)
 
-	// Show deprecation warnings only for known values.
-	if a.GetDeprecationMessage() != "" && !attributeConfig.IsNull() && !attributeConfig.IsUnknown() {
-		// Dynamic values need to perform more logic to check the config value for null/unknown-ness
-		dynamicValuable, ok := attributeConfig.(basetypes.DynamicValuable)
-		if !ok {
-			resp.Diagnostics.AddAttributeWarning(
-				req.AttributePath,
-				"Attribute Deprecated",
-				a.GetDeprecationMessage(),
-			)
-			return
-		}
+	// Show deprecation warnings only for known values or unknown values with a "not null" refinement.
+	if a.GetDeprecationMessage() != "" {
+		if attributeConfig.IsUnknown() {
+			// If the unknown value will eventually be not null, we return the deprecation message for the practitioner.
+			val, ok := attributeConfig.(attr.ValueWithNotNullRefinement)
+			if ok {
+				if _, notNull := val.NotNullRefinement(); notNull {
+					resp.Diagnostics.AddAttributeWarning(
+						req.AttributePath,
+						"Attribute Deprecated",
+						a.GetDeprecationMessage(),
+					)
+					return
+				}
+			}
+		} else if !attributeConfig.IsNull() && !attributeConfig.IsUnknown() {
+			// Dynamic values need to perform more logic to check the config value for null/unknown-ness
+			dynamicValuable, ok := attributeConfig.(basetypes.DynamicValuable)
+			if !ok {
+				resp.Diagnostics.AddAttributeWarning(
+					req.AttributePath,
+					"Attribute Deprecated",
+					a.GetDeprecationMessage(),
+				)
+				return
+			}
 
-		dynamicConfigVal, diags := dynamicValuable.ToDynamicValue(ctx)
-		resp.Diagnostics.Append(diags...)
-		if diags.HasError() {
-			return
-		}
+			dynamicConfigVal, diags := dynamicValuable.ToDynamicValue(ctx)
+			resp.Diagnostics.Append(diags...)
+			if diags.HasError() {
+				return
+			}
 
-		// For dynamic values, it's possible to be known when only the type is known.
-		// The underlying value can still be null or unknown, so check for that here
-		if !dynamicConfigVal.IsUnderlyingValueNull() && !dynamicConfigVal.IsUnderlyingValueUnknown() {
-			resp.Diagnostics.AddAttributeWarning(
-				req.AttributePath,
-				"Attribute Deprecated",
-				a.GetDeprecationMessage(),
-			)
+			// For dynamic values, it's possible to be known when only the type is known.
+			// The underlying value can still be null or unknown, so check for that here
+			if !dynamicConfigVal.IsUnderlyingValueNull() && !dynamicConfigVal.IsUnderlyingValueUnknown() {
+				resp.Diagnostics.AddAttributeWarning(
+					req.AttributePath,
+					"Attribute Deprecated",
+					a.GetDeprecationMessage(),
+				)
+			}
 		}
 	}
 }

internal/fwserver/attribute_validation_test.go

@@ -11,6 +11,7 @@ import (
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/hashicorp/terraform-plugin-go/tftypes"
+	tfrefinement "github.com/hashicorp/terraform-plugin-go/tftypes/refinement"
 
 	"github.com/hashicorp/terraform-plugin-framework/attr"
 	"github.com/hashicorp/terraform-plugin-framework/diag"
@@ -490,6 +491,40 @@ func TestAttributeValidate(t *testing.T) {
 			},
 			resp: ValidateAttributeResponse{},
 		},
+		"deprecation-message-unknown-with-not-null-refinement": {
+			req: ValidateAttributeRequest{
+				AttributePath: path.Root("test"),
+				Config: tfsdk.Config{
+					Raw: tftypes.NewValue(tftypes.Object{
+						AttributeTypes: map[string]tftypes.Type{
+							"test": tftypes.String,
+						},
+					}, map[string]tftypes.Value{
+						"test": tftypes.NewValue(tftypes.String, tftypes.UnknownValue).Refine(tfrefinement.Refinements{
+							tfrefinement.KeyNullness: tfrefinement.NewNullness(false),
+						}),
+					}),
+					Schema: testschema.Schema{
+						Attributes: map[string]fwschema.Attribute{
+							"test": testschema.Attribute{
+								Type:               types.StringType,
+								Optional:           true,
+								DeprecationMessage: "Use something else instead.",
+							},
+						},
+					},
+				},
+			},
+			resp: ValidateAttributeResponse{
+				Diagnostics: diag.Diagnostics{
+					diag.NewAttributeWarningDiagnostic(
+						path.Root("test"),
+						"Attribute Deprecated",
+						"Use something else instead.",
+					),
+				},
+			},
+		},
 		"deprecation-message-dynamic-underlying-value-unknown": {
 			req: ValidateAttributeRequest{
 				AttributePath: path.Root("test"),

internal/testing/testtypes/numberwithvalidateattribute.go

@@ -64,7 +64,7 @@ func (v NumberValueWithValidateAttributeError) Equal(value attr.Value) bool {
 		return false
 	}
 
-	return v == other
+	return v.Equal(other)
 }
 
 func (v NumberValueWithValidateAttributeError) IsNull() bool {
@@ -92,7 +92,7 @@ func (t NumberTypeWithValidateAttributeWarning) Equal(o attr.Type) bool {
 	if !ok {
 		return false
 	}
-	return t == other
+	return t.NumberType.Equal(other.NumberType)
 }
 
 func (t NumberTypeWithValidateAttributeWarning) ValueFromTerraform(ctx context.Context, in tftypes.Value) (attr.Value, error) {
@@ -134,7 +134,7 @@ func (v NumberValueWithValidateAttributeWarning) Equal(value attr.Value) bool {
 		return false
 	}
 
-	return v.InternalNumber.Number.Equal(other.InternalNumber.Number)
+	return v.InternalNumber.Equal(other.InternalNumber)
 }
 
 func (v NumberValueWithValidateAttributeWarning) IsNull() bool {

internal/testing/testtypes/stringwithvalidateattribute.go

@@ -64,7 +64,7 @@ func (v StringValueWithValidateAttributeError) Equal(value attr.Value) bool {
 		return false
 	}
 
-	return v == other
+	return v.InternalString.Equal(other.InternalString)
 }
 
 func (v StringValueWithValidateAttributeError) IsNull() bool {
@@ -134,7 +134,7 @@ func (v StringValueWithValidateAttributeWarning) Equal(value attr.Value) bool {
 		return false
 	}
 
-	return v == other
+	return v.InternalString.Equal(other.InternalString)
 }
 
 func (v StringValueWithValidateAttributeWarning) IsNull() bool {

internal/testing/testtypes/stringwithvalidateparameter.go

@@ -64,7 +64,7 @@ func (v StringValueWithValidateParameterError) Equal(value attr.Value) bool {
 		return false
 	}
 
-	return v == other
+	return v.InternalString.Equal(other.InternalString)
 }
 
 func (v StringValueWithValidateParameterError) IsNull() bool {

resource/schema/boolplanmodifier/will_not_be_null.go

@@ -0,0 +1,50 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package boolplanmodifier
+
+import (
+	"context"
+
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
+)
+
+// WillNotBeNull returns a plan modifier that will add a refinement to an unknown planned value
+// which promises that the final value will not be null.
+//
+// This unknown value refinement allows Terraform to validate more of the configuration during plan
+// and evaluate conditional logic in meta-arguments such as "count":
+//
+//	resource "examplecloud_thing" "b" {
+//		// Will successfully evaluate during plan with a "not null" refinement on "bool_attribute"
+//		count = examplecloud_thing.a.bool_attribute != null ? 1 : 0
+//
+//		// .. resource config
+//	}
+func WillNotBeNull() planmodifier.Bool {
+	return willNotBeNullModifier{}
+}
+
+type willNotBeNullModifier struct{}
+
+func (m willNotBeNullModifier) Description(_ context.Context) string {
+	return "Promises the value of this attribute will not be null once it becomes known"
+}
+
+func (m willNotBeNullModifier) MarkdownDescription(_ context.Context) string {
+	return "Promises the value of this attribute will not be null once it becomes known"
+}
+
+func (m willNotBeNullModifier) PlanModifyBool(ctx context.Context, req planmodifier.BoolRequest, resp *planmodifier.BoolResponse) {
+	// Do nothing if there is a known planned value.
+	if !req.PlanValue.IsUnknown() {
+		return
+	}
+
+	// Do nothing if there is an unknown configuration value, otherwise interpolation gets messed up.
+	if req.ConfigValue.IsUnknown() {
+		return
+	}
+
+	resp.PlanValue = req.PlanValue.RefineAsNotNull()
+}