Add a doc for numeric IDs

Fixes #352

docs/resource-ids.md

@@ -0,0 +1,51 @@
+# Resource IDs
+
+Every Pulumi resource must have an `"id"` field. `"id"` must be a string, and it must be
+set by the provider (`Computed` and *not* `Optional` in Terraform parlance).
+
+## SDKv1 and SDKv2 Based Providers
+
+The ID requirement is easy to satisfy for SDKv{1,2} based providers since both SDKs
+require an ID field of type string set on the provider. If the provider being bridged is
+based on SDKv1 or SDKv2, then the bridge handles Pulumi's ID field without intervention.
+
+## PF Based Providers
+
+Most PF based providers have an attribute called `"id"` of the right kind for the bridge
+to use. If your provider doesn't, then you will see an error when `make tfgen` is
+run. Each error has a different kind of resolution.
+
+### ID of the wrong type
+```
+error: Resource dnsimple_email_forward has a problem: "id" attribute is of type "int", expected type "string". To map this resource consider overriding the SchemaInfo.Type field or specifying ResourceInfo.ComputeID.
+```
+
+This error happens when the upstream resource has an ID but it's not a string. You can fix
+it by setting the `SchemaInfo.Type` override for the `"id"` field:
+
+```go
+			"dnsimple_email_forward": {
+				Fields: map[string]*tfbridge.SchemaInfo{
+					"id": {Type: "string"},
+				},
+			},
+```
+
+
+For providers[^1] where every resource's ID has the wrong type, you can use a `for` loop to apply this:
+
+```go
+	prov.P.ResourcesMap().Range(func(key string, value shim.Resource) bool {
+		if value.Schema().Get("id").Type() != shim.TypeString {
+			r := prov.Resources[key]
+			if r.Fields == nil {
+				r.Fields = make(map[string]*tfbridge.SchemaInfo, 1)
+			}
+			r.Fields["id"] = &tfbridge.SchemaInfo{Type: "string"}
+		}
+		return true
+	})
+```
+
+
+[^1]: https://github.com/pulumi/pulumi-dnsimple/blob/7d7e5f3d88082306f15c3600f3481516ae19454a/provider/resources.go#L126-L140

pf/internal/check/checks.go

@@ -19,7 +19,6 @@ import (
 	"fmt"
 
 	"github.com/pulumi/pulumi/sdk/v3/go/common/diag"
-	"github.com/pulumi/pulumi/sdk/v3/go/common/tokens"
 
 	"github.com/pulumi/pulumi-terraform-bridge/pf/internal/muxer"
 	"github.com/pulumi/pulumi-terraform-bridge/v3/pkg/tfbridge"
@@ -58,15 +57,13 @@ func checkIDProperties(sink diag.Sink, info tfbridge.ProviderInfo, isPFResource
 		if resourceHasComputeID(info, rname) {
 			return true
 		}
-		ok, reason := resourceHasRegularID(resource, info.Resources[rname])
-		if ok {
+		err := resourceHasRegularID(rname, resource, info.Resources[rname])
+		if err == nil {
 			return true
 		}
-		m := fmt.Sprintf("Resource %s has a problem: %s. "+
-			"To map this resource consider specifying ResourceInfo.ComputeID",
-			rname, reason)
+
 		errors++
-		sink.Errorf(&diag.Diag{Message: m})
+		sink.Errorf(&diag.Diag{Message: resourceError{rname, err}.Error()})
 
 		return true
 	})
@@ -78,26 +75,79 @@ func checkIDProperties(sink diag.Sink, info tfbridge.ProviderInfo, isPFResource
 	return nil
 }
 
-func resourceHasRegularID(resource shim.Resource, resourceInfo *tfbridge.ResourceInfo) (bool, string) {
+type resourceError struct {
+	token string
+	err   error
+}
+
+func (err resourceError) Error() string {
+	msg := fmt.Sprintf("Resource %s has a problem", err.token)
+	if err.err != nil {
+		msg += ": " + err.err.Error()
+	}
+	return msg
+}
+
+type errSensativeID struct {
+	token string
+}
+
+func (err errSensativeID) Error() string {
+	msg := `"id" attribute is sensitive, but cannot be kept secret.`
+	if err.token != "" {
+		msg += fmt.Sprintf(
+			" To accept exposing ID, set `ProviderInfo.Resources[%q].Fields[%q].Secret = tfbridge.True()`",
+			err.token, "id")
+	}
+	return msg
+}
+
+type errWrongIDType struct {
+	actualType string
+}
+
+func (err errWrongIDType) Error() string {
+	msg := `"id" attribute is not of type "string"`
+	const postfix = ". To map this resource consider overriding the SchemaInfo.Type" +
+		" field or specifying ResourceInfo.ComputeID"
+	if err.actualType != "" {
+		msg = fmt.Sprintf(
+			`"id" attribute is of type %q, expected type "string"`,
+			err.actualType)
+	}
+	return msg + postfix
+}
+
+type errMissingIDAttribute struct{}
+
+func (errMissingIDAttribute) Error() string {
+	return `no "id" attribute. To map this resource consider specifying ResourceInfo.ComputeID`
+}
+
+func resourceHasRegularID(rname string, resource shim.Resource, resourceInfo *tfbridge.ResourceInfo) error {
 	idSchema, gotID := resource.Schema().GetOk("id")
 	if !gotID {
-		return false, `no "id" attribute`
+		return errMissingIDAttribute{}
 	}
-	var typeOverride tokens.Type
+	var info tfbridge.SchemaInfo
 	if resourceInfo != nil {
 		if id := resourceInfo.Fields["id"]; id != nil {
-			typeOverride = id.Type
+			info = *id
 		}
 	}
 
 	// If the user over-rode the type to be a string, don't reject.
-	if idSchema.Type() != shim.TypeString && typeOverride != "string" {
-		return false, `"id" attribute is not of type String`
+	if idSchema.Type() != shim.TypeString && info.Type != "string" {
+		actual := idSchema.Type().String()
+		if info.Type != "" {
+			actual = string(info.Type)
+		}
+		return errWrongIDType{actualType: actual}
 	}
-	if idSchema.Sensitive() {
-		return false, `"id" attribute is sensitive`
+	if idSchema.Sensitive() && (info.Secret == nil || !*info.Secret) {
+		return errSensativeID{rname}
 	}
-	return true, ""
+	return nil
 }
 
 func resourceHasComputeID(info tfbridge.ProviderInfo, resname string) bool {