deps: Remove github.com/hashicorp/go-multierror direct dependency (#1247)

Reference: hashicorp/terraform-plugin-testing#99

Similar to terraform-plugin-testing, now that this Go module is Go 1.20+, we can use native `errors.Join()` functionality for joining multiple errors.

To fully remove the dependency, will need to update some other dependencies as well, e.g.

```
# github.com/hashicorp/go-multierror
github.com/hashicorp/terraform-plugin-sdk/v2/internal/plugintest
github.com/hashicorp/hc-install
github.com/hashicorp/go-multierror
```

Author: bflad

go.mod

@@ -6,7 +6,6 @@ require (
 	github.com/google/go-cmp v0.5.9
 	github.com/hashicorp/go-cty v1.4.1-0.20200414143053-d3edf31b6320
 	github.com/hashicorp/go-hclog v1.5.0
-	github.com/hashicorp/go-multierror v1.1.1
 	github.com/hashicorp/go-plugin v1.5.1
 	github.com/hashicorp/go-uuid v1.0.3
 	github.com/hashicorp/go-version v1.6.0
@@ -35,6 +34,7 @@ require (
 	github.com/hashicorp/errwrap v1.0.0 // indirect
 	github.com/hashicorp/go-checkpoint v0.5.0 // indirect
 	github.com/hashicorp/go-cleanhttp v0.5.2 // indirect
+	github.com/hashicorp/go-multierror v1.1.1 // indirect
 	github.com/hashicorp/terraform-registry-address v0.2.2 // indirect
 	github.com/hashicorp/terraform-svchost v0.1.1 // indirect
 	github.com/hashicorp/yamux v0.0.0-20181012175058-2f1d1f20f75d // indirect

helper/customdiff/compose.go

@@ -5,8 +5,7 @@ package customdiff
 
 import (
 	"context"
-
-	"github.com/hashicorp/go-multierror"
+	"errors"
 
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
 )
@@ -48,14 +47,14 @@ import (
 //	}
 func All(funcs ...schema.CustomizeDiffFunc) schema.CustomizeDiffFunc {
 	return func(ctx context.Context, d *schema.ResourceDiff, meta interface{}) error {
-		var err error
+		var errs []error
 		for _, f := range funcs {
 			thisErr := f(ctx, d, meta)
 			if thisErr != nil {
-				err = multierror.Append(err, thisErr)
+				errs = append(errs, thisErr)
 			}
 		}
-		return err
+		return errors.Join(errs...)
 	}
 }
 

helper/customdiff/compose_test.go

@@ -6,29 +6,30 @@ package customdiff
 import (
 	"context"
 	"errors"
-	"strings"
 	"testing"
 
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
 )
 
 func TestAll(t *testing.T) {
 	var aCalled, bCalled, cCalled bool
+	aErr := errors.New("A bad")
+	cErr := errors.New("C bad")
 
 	provider := testProvider(
 		map[string]*schema.Schema{},
 		All(
 			func(_ context.Context, d *schema.ResourceDiff, meta interface{}) error {
 				aCalled = true
-				return errors.New("A bad")
+				return aErr
 			},
 			func(_ context.Context, d *schema.ResourceDiff, meta interface{}) error {
 				bCalled = true
 				return nil
 			},
 			func(_ context.Context, d *schema.ResourceDiff, meta interface{}) error {
 				cCalled = true
-				return errors.New("C bad")
+				return cErr
 			},
 		),
 	)
@@ -46,11 +47,11 @@ func TestAll(t *testing.T) {
 	if err == nil {
 		t.Fatal("Diff succeeded; want error")
 	}
-	if s, sub := err.Error(), "* A bad"; !strings.Contains(s, sub) {
-		t.Errorf("Missing substring %q in error message %q", sub, s)
+	if !errors.Is(err, aErr) {
+		t.Errorf("Missing substring %q in error message %q", aErr, err)
 	}
-	if s, sub := err.Error(), "* C bad"; !strings.Contains(s, sub) {
-		t.Errorf("Missing substring %q in error message %q", sub, s)
+	if !errors.Is(err, cErr) {
+		t.Errorf("Missing substring %q in error message %q", cErr, err)
 	}
 
 	if !aCalled {

helper/resource/testing.go

@@ -15,7 +15,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/hashicorp/go-multierror"
 	"github.com/mitchellh/go-testing-interface"
 
 	"github.com/hashicorp/terraform-plugin-go/tfprotov5"
@@ -836,15 +835,15 @@ func ComposeTestCheckFunc(fs ...TestCheckFunc) TestCheckFunc {
 // TestCheckFuncs and aggregates failures.
 func ComposeAggregateTestCheckFunc(fs ...TestCheckFunc) TestCheckFunc {
 	return func(s *terraform.State) error {
-		var result *multierror.Error
+		var result []error
 
 		for i, f := range fs {
 			if err := f(s); err != nil {
-				result = multierror.Append(result, fmt.Errorf("Check %d/%d error: %s", i+1, len(fs), err))
+				result = append(result, fmt.Errorf("Check %d/%d error: %w", i+1, len(fs), err))
 			}
 		}
 
-		return result.ErrorOrNil()
+		return errors.Join(result...)
 	}
 }
 

helper/resource/testing_test.go

@@ -13,7 +13,6 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/hashicorp/go-multierror"
 	testinginterface "github.com/mitchellh/go-testing-interface"
 
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/schema"
@@ -88,26 +87,27 @@ func TestParallelTest(t *testing.T) {
 }
 
 func TestComposeAggregateTestCheckFunc(t *testing.T) {
+	err1 := errors.New("Error 1")
 	check1 := func(s *terraform.State) error {
-		return errors.New("Error 1")
+		return err1
 	}
 
+	err2 := errors.New("Error 2")
 	check2 := func(s *terraform.State) error {
-		return errors.New("Error 2")
+		return err2
 	}
 
 	f := ComposeAggregateTestCheckFunc(check1, check2)
 	err := f(nil)
 	if err == nil {
-		t.Fatalf("Expected errors")
+		t.Fatal("expected error, got none")
 	}
 
-	multi := err.(*multierror.Error)
-	if !strings.Contains(multi.Errors[0].Error(), "Error 1") {
-		t.Fatalf("Expected Error 1, Got %s", multi.Errors[0])
+	if !errors.Is(err, err1) {
+		t.Errorf("expected %s, got: %s", err1, err)
 	}
-	if !strings.Contains(multi.Errors[1].Error(), "Error 2") {
-		t.Fatalf("Expected Error 2, Got %s", multi.Errors[1])
+	if !errors.Is(err, err2) {
+		t.Errorf("expected %s, got: %s", err2, err)
 	}
 }
 

helper/schema/provider.go

@@ -12,8 +12,6 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/hashicorp/go-multierror"
-
 	"github.com/hashicorp/terraform-plugin-go/tfprotov5"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/diag"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/internal/configs/configschema"
@@ -130,10 +128,10 @@ func (p *Provider) InternalValidate() error {
 		return errors.New("ConfigureFunc and ConfigureContextFunc must not both be set")
 	}
 
-	var validationErrors error
+	var validationErrors []error
 	sm := schemaMap(p.Schema)
 	if err := sm.InternalValidate(sm); err != nil {
-		validationErrors = multierror.Append(validationErrors, err)
+		validationErrors = append(validationErrors, err)
 	}
 
 	// Provider-specific checks
@@ -145,17 +143,17 @@ func (p *Provider) InternalValidate() error {
 
 	for k, r := range p.ResourcesMap {
 		if err := r.InternalValidate(nil, true); err != nil {
-			validationErrors = multierror.Append(validationErrors, fmt.Errorf("resource %s: %s", k, err))
+			validationErrors = append(validationErrors, fmt.Errorf("resource %s: %s", k, err))
 		}
 	}
 
 	for k, r := range p.DataSourcesMap {
 		if err := r.InternalValidate(nil, false); err != nil {
-			validationErrors = multierror.Append(validationErrors, fmt.Errorf("data source %s: %s", k, err))
+			validationErrors = append(validationErrors, fmt.Errorf("data source %s: %s", k, err))
 		}
 	}
 
-	return validationErrors
+	return errors.Join(validationErrors...)
 }
 
 func isReservedProviderFieldName(name string) bool {

internal/diagutils/diagutils.go

@@ -7,7 +7,6 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/terraform-plugin-sdk/v2/diag"
 )
 
@@ -28,7 +27,7 @@ func (diags ErrorDiags) Errors() []error {
 }
 
 func (diags ErrorDiags) Error() string {
-	return multierror.ListFormatFunc(diags.Errors())
+	return errors.Join(diags.Errors()...).Error()
 }
 
 type WarningDiags diag.Diagnostics

terraform/state.go

@@ -7,6 +7,7 @@ import (
 	"bufio"
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"log"
 	"os"
@@ -17,7 +18,6 @@ import (
 	"sync"
 
 	"github.com/hashicorp/go-cty/cty"
-	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/go-uuid"
 	"github.com/mitchellh/copystructure"
 
@@ -287,7 +287,7 @@ func (s *State) Validate() error {
 	s.Lock()
 	defer s.Unlock()
 
-	var result error
+	var result []error
 
 	// !!!! FOR DEVELOPERS !!!!
 	//
@@ -309,7 +309,7 @@ func (s *State) Validate() error {
 
 			key := strings.Join(ms.Path, ".")
 			if _, ok := found[key]; ok {
-				result = multierror.Append(result, fmt.Errorf(
+				result = append(result, fmt.Errorf(
 					strings.TrimSpace(stateValidateErrMultiModule), key))
 				continue
 			}
@@ -318,7 +318,7 @@ func (s *State) Validate() error {
 		}
 	}
 
-	return result
+	return errors.Join(result...)
 }
 
 // Remove removes the item in the state at the given address, returning