Standardize on only two value dumping/diffing libraries

Due to the quite messy heritage of this codebase -- including a large part
of it being just a fork of my earlier personal project ZCL -- there were
many different conventions for how to pretty-print and diff values in the
tests in different parts of the codebase.

To reduce the dependency sprawl, this commit now standardizes on:
  - github.com/davecgh/go-spew for pretty-printing
  - github.com/google/go-cmp for diffing

These two dependencies were already present anyway, are the most general
out of all of the candidates, and are also already in use by at least some
of HCL's most significant callers, such as HashiCorp Terraform.

The version of go-cmp we were previously using seems to have a bug that
causes the tests to crash when run under the Go race detector, so I've
also upgraded that dependency to latest here to clear that bug.

8 files changed, 61 insertions, 89 deletions

diff --git a/go.mod b/go.mod
index a800502..d9d4da4 100644
--- a/go.mod
+++ b/go.mod
@@ -4,15 +4,11 @@ go 1.18
 
 require (
 	github.com/agext/levenshtein v1.2.1
-	github.com/apparentlymart/go-dump v0.0.0-20180507223929-23540a00eaa3
 	github.com/apparentlymart/go-textseg/v15 v15.0.0
 	github.com/davecgh/go-spew v1.1.1
 	github.com/go-test/deep v1.0.3
-	github.com/google/go-cmp v0.3.1
-	github.com/kr/pretty v0.1.0
-	github.com/kylelemons/godebug v0.0.0-20170820004349-d65d576e9348
+	github.com/google/go-cmp v0.6.0
 	github.com/mitchellh/go-wordwrap v0.0.0-20150314170334-ad45545899c7
-	github.com/sergi/go-diff v1.0.0
 	github.com/spf13/pflag v1.0.2
 	github.com/zclconf/go-cty v1.13.0
 	github.com/zclconf/go-cty-debug v0.0.0-20191215020915-b22d67c1ba0b
@@ -22,9 +18,6 @@ require (
 
 require (
 	github.com/apparentlymart/go-textseg/v13 v13.0.0 // indirect
-	github.com/kr/text v0.1.0 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/stretchr/testify v1.2.2 // indirect
 	golang.org/x/mod v0.8.0 // indirect
 	golang.org/x/sys v0.5.0 // indirect
 	golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1 // indirect
diff --git a/go.sum b/go.sum
index 62014eb..08ed23e 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,5 @@
 github.com/agext/levenshtein v1.2.1 h1:QmvMAjj2aEICytGiWzmxoE0x2KZvE0fvmqMOfy2tjT8=
 github.com/agext/levenshtein v1.2.1/go.mod h1:JEDfjyjHDjOF/1e4FlBE/PkbqA9OfWu2ki2W0IB5558=
-github.com/apparentlymart/go-dump v0.0.0-20180507223929-23540a00eaa3 h1:ZSTrOEhiM5J5RFxEaFvMZVEAM1KvT1YzbEOwB2EAGjA=
-github.com/apparentlymart/go-dump v0.0.0-20180507223929-23540a00eaa3/go.mod h1:oL81AME2rN47vu18xqj1S1jPIPuN7afo62yKTNn3XMM=
 github.com/apparentlymart/go-textseg v1.0.0/go.mod h1:z96Txxhf3xSFMPmb5X/1W05FF/Nj9VFpLOpjS5yuumk=
 github.com/apparentlymart/go-textseg/v13 v13.0.0 h1:Y+KvPE1NYz0xl601PVImeQfFyEy6iT90AvPUL1NNfNw=
 github.com/apparentlymart/go-textseg/v13 v13.0.0/go.mod h1:ZK2fH7c4NqDTLtiYLvIkEghdlcqw7yxLeM89kiTRPUo=
@@ -12,25 +10,17 @@ github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/go-test/deep v1.0.3 h1:ZrJSEWsXzPOxaZnFteGEfooLba+ju3FYIbOrS+rQd68=
 github.com/go-test/deep v1.0.3/go.mod h1:wGDj63lr65AM2AQyKZd/NYHGb0R+1RLqB8NKt3aSFNA=
 github.com/golang/protobuf v1.1.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
-github.com/google/go-cmp v0.3.1 h1:Xye71clBPdm5HgqGwUkwhbynsUJZhDbS20FvLhQ2izg=
 github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
-github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
+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/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/kylelemons/godebug v0.0.0-20170820004349-d65d576e9348 h1:MtvEpTB6LX3vkb4ax0b5D2DHbNAUsen0Gx5wZoq3lV4=
 github.com/kylelemons/godebug v0.0.0-20170820004349-d65d576e9348/go.mod h1:B69LEHPfb2qLo0BaaOLcbitczOKLWTsrBG9LczfCD4k=
 github.com/mitchellh/go-wordwrap v0.0.0-20150314170334-ad45545899c7 h1:DpOJ2HYzCv8LZP15IdmG+YdwD2luVPHITV96TkirNBM=
 github.com/mitchellh/go-wordwrap v0.0.0-20150314170334-ad45545899c7/go.mod h1:ZXFpozHsX6DPmq2I0TCekCxypsnAUbP2oI0UX1GXzOo=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
-github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/spf13/pflag v1.0.2 h1:Fy0orTDgHdbnzHcsOgfCN4LtHf0ec3wwtiwJqwvf3Gc=
 github.com/spf13/pflag v1.0.2/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
-github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
-github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/vmihailenco/msgpack v3.3.3+incompatible/go.mod h1:fy3FlTQTDXWkZ7Bh6AcGMlsjHatGryHQYUTf1ShIgkk=
 github.com/zclconf/go-cty v1.2.0/go.mod h1:hOPWgoHbaTUnI5k4D2ld+GRpFJSCe6bCM7m1q/N4PQ8=
 github.com/zclconf/go-cty v1.13.0 h1:It5dfKTTZHe9aeppbNOda3mN7Ag7sg6QkBNm6TkyFa0=
diff --git a/hcldec/spec_test.go b/hcldec/spec_test.go
index 1b0594d..a88066b 100644
--- a/hcldec/spec_test.go
+++ b/hcldec/spec_test.go
@@ -8,7 +8,6 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/apparentlymart/go-dump/dump"
 	"github.com/google/go-cmp/cmp"
 	"github.com/zclconf/go-cty-debug/ctydebug"
 	"github.com/zclconf/go-cty/cty"
@@ -98,7 +97,16 @@ bar = barval
 			},
 		}
 		if !reflect.DeepEqual(gotVars, wantVars) {
-			t.Errorf("wrong Variables result\ngot: %s\nwant: %s", dump.Value(gotVars), dump.Value(wantVars))
+			t.Errorf(
+				"wrong Variables result\n%s",
+				cmp.Diff(
+					wantVars, gotVars,
+					cmp.AllowUnexported(
+						hcl.TraverseRoot{},
+					),
+					ctydebug.CmpOptions,
+				),
+			)
 		}
 
 		ctx := &hcl.EvalContext{
diff --git a/hclsyntax/parser_test.go b/hclsyntax/parser_test.go
index 90a7583..10825f1 100644
--- a/hclsyntax/parser_test.go
+++ b/hclsyntax/parser_test.go
@@ -5,19 +5,16 @@ package hclsyntax
 
 import (
 	"fmt"
+	"sync"
 	"testing"
 
-	"github.com/go-test/deep"
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	"github.com/hashicorp/hcl/v2"
+	"github.com/zclconf/go-cty-debug/ctydebug"
 	"github.com/zclconf/go-cty/cty"
 )
 
-func init() {
-	deep.MaxDepth = 999
-}
-
 func TestParseConfig(t *testing.T) {
 	tests := []struct {
 		input     string
@@ -2197,6 +2194,7 @@ block "valid" {}
 					"a": {
 						Name: "a",
 						Expr: &LiteralValueExpr{
+							Val: cty.DynamicVal,
 							SrcRange: hcl.Range{
 								Start: hcl.Pos{Line: 1, Column: 5, Byte: 4},
 								End:   hcl.Pos{Line: 1, Column: 6, Byte: 5},
@@ -2235,6 +2233,7 @@ block "valid" {}
 					"a": {
 						Name: "a",
 						Expr: &LiteralValueExpr{
+							Val: cty.DynamicVal,
 							SrcRange: hcl.Range{
 								Start: hcl.Pos{Line: 1, Column: 5, Byte: 4},
 								End:   hcl.Pos{Line: 1, Column: 6, Byte: 5},
@@ -2687,11 +2686,23 @@ block "valid" {}
 			}
 
 			got := file.Body
-
-			if diff := deep.Equal(got, test.want); diff != nil {
-				for _, problem := range diff {
-					t.Errorf(problem)
-				}
+			diff := cmp.Diff(
+				test.want, got,
+				cmp.AllowUnexported(
+					Body{},
+					AnonSymbolExpr{},
+					hcl.TraverseRoot{},
+					hcl.TraverseAttr{},
+					hcl.TraverseIndex{},
+				),
+				cmpopts.IgnoreUnexported(
+					sync.Mutex{},
+					sync.RWMutex{},
+				),
+				ctydebug.CmpOptions,
+			)
+			if diff != "" {
+				t.Errorf("wrong result\n%s", diff)
 			}
 		})
 	}
@@ -4006,10 +4017,8 @@ func TestParseConfigDiagnostics(t *testing.T) {
 			t.Logf("\n%s", test.input)
 			_, diags := ParseConfig([]byte(test.input), "test.hcl", hcl.InitialPos)
 
-			if diff := deep.Equal(diags, test.want); diff != nil {
-				for _, problem := range diff {
-					t.Errorf(problem)
-				}
+			if diff := cmp.Diff(test.want, diags); diff != "" {
+				t.Errorf("wrong diagnostics\n%s", diff)
 			}
 		})
 	}
diff --git a/hclsyntax/structure_test.go b/hclsyntax/structure_test.go
index c86dc32..180425b 100644
--- a/hclsyntax/structure_test.go
+++ b/hclsyntax/structure_test.go
@@ -8,8 +8,10 @@ import (
 	"reflect"
 	"testing"
 
+	"github.com/davecgh/go-spew/spew"
+	"github.com/google/go-cmp/cmp"
 	"github.com/hashicorp/hcl/v2"
-	"github.com/kylelemons/godebug/pretty"
+	"github.com/zclconf/go-cty-debug/ctydebug"
 	"github.com/zclconf/go-cty/cty"
 )
 
@@ -390,12 +392,6 @@ func TestBodyContent(t *testing.T) {
 		},
 	}
 
-	prettyConfig := &pretty.Config{
-		Diffable:          true,
-		IncludeUnexported: true,
-		PrintStringers:    true,
-	}
-
 	for i, test := range tests {
 		t.Run(fmt.Sprintf("%02d", i), func(t *testing.T) {
 			var got *hcl.BodyContent
@@ -416,7 +412,7 @@ func TestBodyContent(t *testing.T) {
 			if !reflect.DeepEqual(got, test.want) {
 				t.Errorf(
 					"wrong result\ndiff: %s",
-					prettyConfig.Compare(test.want, got),
+					cmp.Diff(test.want, got),
 				)
 			}
 		})
@@ -499,7 +495,7 @@ func TestBodyJustAttributes(t *testing.T) {
 					},
 				},
 				hiddenAttrs: map[string]struct{}{
-					"foo": struct{}{},
+					"foo": {},
 				},
 			},
 			hcl.Attributes{},
@@ -507,12 +503,6 @@ func TestBodyJustAttributes(t *testing.T) {
 		},
 	}
 
-	prettyConfig := &pretty.Config{
-		Diffable:          true,
-		IncludeUnexported: true,
-		PrintStringers:    true,
-	}
-
 	for i, test := range tests {
 		t.Run(fmt.Sprintf("%02d", i), func(t *testing.T) {
 			got, diags := test.body.JustAttributes()
@@ -524,11 +514,15 @@ func TestBodyJustAttributes(t *testing.T) {
 				}
 			}
 
-			if !reflect.DeepEqual(got, test.want) {
+			diff := cmp.Diff(
+				test.want, got,
+				ctydebug.CmpOptions,
+			)
+			if diff != "" {
 				t.Errorf(
 					"wrong result\nbody: %s\ndiff: %s",
-					prettyConfig.Sprint(test.body),
-					prettyConfig.Compare(test.want, got),
+					spew.Sdump(test.body),
+					diff,
 				)
 			}
 		})
diff --git a/hclsyntax/variables_test.go b/hclsyntax/variables_test.go
index c841d94..9eb3d41 100644
--- a/hclsyntax/variables_test.go
+++ b/hclsyntax/variables_test.go
@@ -8,8 +8,8 @@ import (
 	"reflect"
 	"testing"
 
+	"github.com/davecgh/go-spew/spew"
 	"github.com/hashicorp/hcl/v2"
-	"github.com/kr/pretty"
 	"github.com/zclconf/go-cty/cty"
 )
 
@@ -300,7 +300,10 @@ func TestVariables(t *testing.T) {
 			got := Variables(test.Expr)
 
 			if !reflect.DeepEqual(got, test.Want) {
-				t.Errorf("wrong result\ngot:  %s\nwant: %s", pretty.Sprint(got), pretty.Sprint(test.Want))
+				t.Errorf(
+					"wrong result\ngot:  %s\nwant: %s",
+					spew.Sdump(got), spew.Sdump(test.Want),
+				)
 			}
 		})
 	}
diff --git a/hclwrite/parser_test.go b/hclwrite/parser_test.go
index e557940..8ccae99 100644
--- a/hclwrite/parser_test.go
+++ b/hclwrite/parser_test.go
@@ -5,15 +5,11 @@ package hclwrite
 
 import (
 	"fmt"
-	"reflect"
 	"testing"
 
 	"github.com/davecgh/go-spew/spew"
-
 	"github.com/google/go-cmp/cmp"
 
-	"github.com/kylelemons/godebug/pretty"
-
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hclsyntax"
 )
@@ -1360,12 +1356,6 @@ func TestPartitionTokens(t *testing.T) {
 		},
 	}
 
-	prettyConfig := &pretty.Config{
-		Diffable:          true,
-		IncludeUnexported: true,
-		PrintStringers:    true,
-	}
-
 	for i, test := range tests {
 		t.Run(fmt.Sprintf("%02d", i), func(t *testing.T) {
 			gotStart, gotEnd := partitionTokens(test.tokens, test.rng)
@@ -1373,7 +1363,7 @@ func TestPartitionTokens(t *testing.T) {
 			if gotStart != test.wantStart || gotEnd != test.wantEnd {
 				t.Errorf(
 					"wrong result\ntokens: %s\nrange: %#v\ngot:   %d, %d\nwant:  %d, %d",
-					prettyConfig.Sprint(test.tokens), test.rng,
+					spew.Sdump(test.tokens), test.rng,
 					gotStart, test.wantStart,
 					gotEnd, test.wantEnd,
 				)
@@ -1437,12 +1427,6 @@ func TestPartitionLeadCommentTokens(t *testing.T) {
 		},
 	}
 
-	prettyConfig := &pretty.Config{
-		Diffable:          true,
-		IncludeUnexported: true,
-		PrintStringers:    true,
-	}
-
 	for i, test := range tests {
 		t.Run(fmt.Sprintf("%02d", i), func(t *testing.T) {
 			gotStart := partitionLeadCommentTokens(test.tokens)
@@ -1450,7 +1434,7 @@ func TestPartitionLeadCommentTokens(t *testing.T) {
 			if gotStart != test.wantStart {
 				t.Errorf(
 					"wrong result\ntokens: %s\ngot:   %d\nwant:  %d",
-					prettyConfig.Sprint(test.tokens),
+					spew.Sdump(test.tokens),
 					gotStart, test.wantStart,
 				)
 			}
@@ -1589,20 +1573,15 @@ foo "bar" "baz" {
 		},
 	}
 
-	prettyConfig := &pretty.Config{
-		Diffable:          true,
-		IncludeUnexported: true,
-		PrintStringers:    true,
-	}
-
 	for _, test := range tests {
 		t.Run(test.input, func(t *testing.T) {
 			got := lexConfig([]byte(test.input))
 
-			if !reflect.DeepEqual(got, test.want) {
-				diff := prettyConfig.Compare(test.want, got)
+			diff := cmp.Diff(test.want, got)
+			if diff != "" {
 				t.Errorf(
-					"wrong result\ninput: %s\ndiff:  %s", test.input, diff,
+					"wrong result\ninput: %s\ndiff:\n%s",
+					test.input, diff,
 				)
 			}
 		})
diff --git a/hclwrite/round_trip_test.go b/hclwrite/round_trip_test.go
index bf306de..9dbb152 100644
--- a/hclwrite/round_trip_test.go
+++ b/hclwrite/round_trip_test.go
@@ -7,7 +7,7 @@ import (
 	"bytes"
 	"testing"
 
-	"github.com/sergi/go-diff/diffmatchpatch"
+	"github.com/google/go-cmp/cmp"
 	"github.com/zclconf/go-cty/cty"
 	"github.com/zclconf/go-cty/cty/function"
 	"github.com/zclconf/go-cty/cty/function/stdlib"
@@ -71,12 +71,8 @@ block {
 			}
 
 			result := wr.Bytes()
-
 			if !bytes.Equal(result, src) {
-				dmp := diffmatchpatch.New()
-				diffs := dmp.DiffMain(string(src), string(result), false)
-				// t.Errorf("wrong result\nresult:\n%s\ninput:\n%s", result, src)
-				t.Errorf("wrong result\ndiff: (red indicates missing lines, and green indicates unexpected lines)\n%s", dmp.DiffPrettyText(diffs))
+				t.Errorf("wrong result\ndiff:\n%s", cmp.Diff(string(src), string(result)))
 			}
 		})
 	}