GC: Use of Ptr extension (#2477)

## Description
Use of Pointer package in /connector/exchange

<!-- Insert PR description-->

## Does this PR need a docs update or release note?
Wanted to extend the package to generics, but it is incomplete

- [x] ⛔ No 

## Type of change

<!--- Please check the type of change your PR introduces: --->
- [x] 🌻 Feature


## Issue(s)

<!-- Can reference multiple issues. Use one of the following "magic words" - "closes, fixes" to auto-close the Github issue. -->
* related  #2474<issue>

## Test Plan

- [x] ⚡ Unit test

src/internal/common/ptr/pointer.go

@@ -1,13 +1,20 @@
 package ptr
 
-// Val helper method for unwrapping strings
+// ptr package is a common package used for pointer
+// access and deserialization.
+
+// Val Generic function for dereferencing pointers.
 // Microsoft Graph saves many variables as string pointers.
 // Function will safely check if the point is nil prior to
 // dereferencing the pointer. If the pointer is nil,
-// an empty string is returned.
+// an empty version of the object is returned.
-func Val(ptr *string) string {
+// Operation does not work on Nested objects.
+// For example:
+// *evt.GetEnd().GetDateTime() will still cause a panic
+// if evt is nil or GetEnd() is nil
+func Val[T any](ptr *T) T {
 	if ptr == nil {
-		return ""
+		return *new(T)
 	}
 
 	return *ptr

src/internal/common/ptr/pointer_test.go

@@ -0,0 +1,99 @@
+package ptr_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+
+	"github.com/alcionai/corso/src/internal/common/ptr"
+)
+
+type PointerSuite struct {
+	suite.Suite
+}
+
+func TestPointerSuite(t *testing.T) {
+	suite.Run(t, new(PointerSuite))
+}
+
+// TestVal checks to ptr derefencing for the
+// following types:
+// - *string
+// - *bool
+// - *time.Time
+func (suite *PointerSuite) TestVal() {
+	var (
+		t          = suite.T()
+		created    *time.Time
+		testString *string
+		testBool   *bool
+		testInt    *int
+		testInt32  *int32
+		testInt64  *int64
+	)
+
+	// String Checks
+	subject := ptr.Val(testString)
+	assert.Empty(t, subject)
+
+	hello := "Hello World"
+	testString = &hello
+	subject = ptr.Val(testString)
+
+	t.Logf("Received: %s", subject)
+	assert.NotEmpty(t, subject)
+
+	// Time Checks
+
+	myTime := ptr.Val(created)
+	assert.Empty(t, myTime)
+	assert.NotNil(t, myTime)
+
+	now := time.Now()
+	created = &now
+	myTime = ptr.Val(created)
+	assert.NotEmpty(t, myTime)
+
+	// Bool Checks
+	truth := true
+	myBool := ptr.Val(testBool)
+	assert.NotNil(t, myBool)
+	assert.False(t, myBool)
+
+	testBool = &truth
+	myBool = ptr.Val(testBool)
+	assert.NotNil(t, myBool)
+	assert.True(t, myBool)
+
+	// Int checks
+	myInt := ptr.Val(testInt)
+	myInt32 := ptr.Val(testInt32)
+	myInt64 := ptr.Val(testInt64)
+
+	assert.NotNil(t, myInt)
+	assert.NotNil(t, myInt32)
+	assert.NotNil(t, myInt64)
+	assert.Empty(t, myInt)
+	assert.Empty(t, myInt32)
+	assert.Empty(t, myInt64)
+
+	num := 4071
+	num32 := int32(num * 32)
+	num64 := int64(num * 2048)
+	testInt = &num
+	testInt32 = &num32
+	testInt64 = &num64
+
+	myInt = ptr.Val(testInt)
+	myInt32 = ptr.Val(testInt32)
+	myInt64 = ptr.Val(testInt64)
+
+	assert.NotNil(t, myInt)
+	assert.NotNil(t, myInt32)
+	assert.NotNil(t, myInt64)
+	assert.NotEmpty(t, myInt)
+	assert.NotEmpty(t, myInt32)
+	assert.NotEmpty(t, myInt64)
+}

src/internal/connector/exchange/api/contacts.go

@@ -3,7 +3,6 @@ package api
 import (
 	"context"
 	"fmt"
-	"time"
 
 	"github.com/alcionai/clues"
 	"github.com/hashicorp/go-multierror"
@@ -13,6 +12,7 @@ import (
 	"github.com/microsoftgraph/msgraph-sdk-go/users"
 	"github.com/pkg/errors"
 
+	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/connector/graph"
 	"github.com/alcionai/corso/src/internal/connector/graph/api"
 	"github.com/alcionai/corso/src/internal/connector/support"
@@ -317,16 +317,8 @@ func (c Contacts) Serialize(
 // ---------------------------------------------------------------------------
 
 func ContactInfo(contact models.Contactable) *details.ExchangeInfo {
-	name := ""
+	name := ptr.Val(contact.GetDisplayName())
-	created := time.Time{}
+	created := ptr.Val(contact.GetCreatedDateTime())
-
-	if contact.GetDisplayName() != nil {
-		name = *contact.GetDisplayName()
-	}
-
-	if contact.GetCreatedDateTime() != nil {
-		created = *contact.GetCreatedDateTime()
-	}
 
 	return &details.ExchangeInfo{
 		ItemType:    details.ExchangeContact,

src/internal/connector/exchange/api/events.go

@@ -14,6 +14,7 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/alcionai/corso/src/internal/common"
+	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/connector/graph"
 	"github.com/alcionai/corso/src/internal/connector/graph/api"
 	"github.com/alcionai/corso/src/internal/connector/support"
@@ -390,11 +391,12 @@ func (c CalendarDisplayable) GetParentFolderId() *string {
 
 func EventInfo(evt models.Eventable) *details.ExchangeInfo {
 	var (
-		organizer, subject string
+		organizer string
-		recurs             bool
+		subject   = ptr.Val(evt.GetSubject())
-		start              = time.Time{}
+		recurs    bool
-		end                = time.Time{}
+		start     = time.Time{}
-		created            = time.Time{}
+		end       = time.Time{}
+		created   = ptr.Val(evt.GetCreatedDateTime())
 	)
 
 	if evt.GetOrganizer() != nil &&
@@ -405,10 +407,6 @@ func EventInfo(evt models.Eventable) *details.ExchangeInfo {
 			GetAddress()
 	}
 
-	if evt.GetSubject() != nil {
-		subject = *evt.GetSubject()
-	}
-
 	if evt.GetRecurrence() != nil {
 		recurs = true
 	}
@@ -437,10 +435,6 @@ func EventInfo(evt models.Eventable) *details.ExchangeInfo {
 		}
 	}
 
-	if evt.GetCreatedDateTime() != nil {
-		created = *evt.GetCreatedDateTime()
-	}
-
 	return &details.ExchangeInfo{
 		ItemType:    details.ExchangeEvent,
 		Organizer:   organizer,

src/internal/connector/exchange/api/mail.go

@@ -3,7 +3,6 @@ package api
 import (
 	"context"
 	"fmt"
-	"time"
 
 	"github.com/alcionai/clues"
 	"github.com/hashicorp/go-multierror"
@@ -13,6 +12,7 @@ import (
 	"github.com/microsoftgraph/msgraph-sdk-go/users"
 	"github.com/pkg/errors"
 
+	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/connector/graph"
 	"github.com/alcionai/corso/src/internal/connector/graph/api"
 	"github.com/alcionai/corso/src/internal/connector/support"
@@ -348,9 +348,9 @@ func (c Mail) Serialize(
 
 func MailInfo(msg models.Messageable) *details.ExchangeInfo {
 	sender := ""
-	subject := ""
+	subject := ptr.Val(msg.GetSubject())
-	received := time.Time{}
+	received := ptr.Val(msg.GetReceivedDateTime())
-	created := time.Time{}
+	created := ptr.Val(msg.GetCreatedDateTime())
 
 	if msg.GetSender() != nil &&
 		msg.GetSender().GetEmailAddress() != nil &&
@@ -358,18 +358,6 @@ func MailInfo(msg models.Messageable) *details.ExchangeInfo {
 		sender = *msg.GetSender().GetEmailAddress().GetAddress()
 	}
 
-	if msg.GetSubject() != nil {
-		subject = *msg.GetSubject()
-	}
-
-	if msg.GetReceivedDateTime() != nil {
-		received = *msg.GetReceivedDateTime()
-	}
-
-	if msg.GetCreatedDateTime() != nil {
-		created = *msg.GetCreatedDateTime()
-	}
-
 	return &details.ExchangeInfo{
 		ItemType: details.ExchangeMail,
 		Sender:   sender,

src/internal/connector/exchange/attachment.go

@@ -25,7 +25,8 @@ const (
 )
 
 func attachmentType(attachment models.Attachmentable) models.AttachmentType {
-	switch *attachment.GetOdataType() {
+	attachmentType := ptr.Val(attachment.GetOdataType())
+	switch attachmentType {
 	case fileAttachmentOdataValue:
 		return models.FILE_ATTACHMENTTYPE
 	case itemAttachmentOdataValue:

src/internal/connector/exchange/service_restore.go

@@ -11,6 +11,7 @@ import (
 	"github.com/pkg/errors"
 
 	"github.com/alcionai/corso/src/internal/common"
+	"github.com/alcionai/corso/src/internal/common/ptr"
 	"github.com/alcionai/corso/src/internal/connector/exchange/api"
 	"github.com/alcionai/corso/src/internal/connector/graph"
 	"github.com/alcionai/corso/src/internal/connector/support"
@@ -71,7 +72,7 @@ func RestoreExchangeContact(
 
 	response, err := service.Client().UsersById(user).ContactFoldersById(destination).Contacts().Post(ctx, contact, nil)
 	if err != nil {
-		name := *contact.GetGivenName()
+		name := ptr.Val(contact.GetGivenName())
 
 		return nil, errors.Wrap(
 			err,
@@ -146,7 +147,8 @@ func RestoreExchangeEvent(
 			errs = support.WrapAndAppend(
 				fmt.Sprintf(
 					"uploading attachment for message %s: %s",
-					*transformedEvent.GetId(), support.ConnectorStackErrorTrace(err),
+					ptr.Val(transformedEvent.GetId()),
+					support.ConnectorStackErrorTrace(err),
 				),
 				err,
 				errs,
@@ -283,12 +285,8 @@ func SendMailToBackStore(
 
 	for _, attachment := range attached {
 		if err := uploadAttachment(ctx, uploader, attachment); err != nil {
-			if attachment.GetOdataType() != nil &&
+			if ptr.Val(attachment.GetOdataType()) == "#microsoft.graph.itemAttachment" {
-				*attachment.GetOdataType() == "#microsoft.graph.itemAttachment" {
+				name := ptr.Val(attachment.GetName())
-				var name string
-				if attachment.GetName() != nil {
-					name = *attachment.GetName()
-				}
 
 				logger.Ctx(ctx).Infow(
 					"item attachment upload not successful. content not accepted by M365 server",