chore: vendor

vendor/gotest.tools/v3/internal/assert/assert.go

@@ -0,0 +1,161 @@
+// Package assert provides internal utilties for assertions.
+package assert
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+	"reflect"
+
+	"gotest.tools/v3/assert/cmp"
+	"gotest.tools/v3/internal/format"
+	"gotest.tools/v3/internal/source"
+)
+
+// LogT is the subset of testing.T used by the assert package.
+type LogT interface {
+	Log(args ...interface{})
+}
+
+type helperT interface {
+	Helper()
+}
+
+const failureMessage = "assertion failed: "
+
+// Eval the comparison and print a failure messages if the comparison has failed.
+func Eval(
+	t LogT,
+	argSelector argSelector,
+	comparison interface{},
+	msgAndArgs ...interface{},
+) bool {
+	if ht, ok := t.(helperT); ok {
+		ht.Helper()
+	}
+	var success bool
+	switch check := comparison.(type) {
+	case bool:
+		if check {
+			return true
+		}
+		logFailureFromBool(t, msgAndArgs...)
+
+	// Undocumented legacy comparison without Result type
+	case func() (success bool, message string):
+		success = runCompareFunc(t, check, msgAndArgs...)
+
+	case nil:
+		return true
+
+	case error:
+		msg := failureMsgFromError(check)
+		t.Log(format.WithCustomMessage(failureMessage+msg, msgAndArgs...))
+
+	case cmp.Comparison:
+		success = RunComparison(t, argSelector, check, msgAndArgs...)
+
+	case func() cmp.Result:
+		success = RunComparison(t, argSelector, check, msgAndArgs...)
+
+	default:
+		t.Log(fmt.Sprintf("invalid Comparison: %v (%T)", check, check))
+	}
+	return success
+}
+
+func runCompareFunc(
+	t LogT,
+	f func() (success bool, message string),
+	msgAndArgs ...interface{},
+) bool {
+	if ht, ok := t.(helperT); ok {
+		ht.Helper()
+	}
+	if success, message := f(); !success {
+		t.Log(format.WithCustomMessage(failureMessage+message, msgAndArgs...))
+		return false
+	}
+	return true
+}
+
+func logFailureFromBool(t LogT, msgAndArgs ...interface{}) {
+	if ht, ok := t.(helperT); ok {
+		ht.Helper()
+	}
+	const stackIndex = 3 // Assert()/Check(), assert(), logFailureFromBool()
+	args, err := source.CallExprArgs(stackIndex)
+	if err != nil {
+		t.Log(err.Error())
+		return
+	}
+
+	const comparisonArgIndex = 1 // Assert(t, comparison)
+	if len(args) <= comparisonArgIndex {
+		t.Log(failureMessage + "but assert failed to find the expression to print")
+		return
+	}
+
+	msg, err := boolFailureMessage(args[comparisonArgIndex])
+	if err != nil {
+		t.Log(err.Error())
+		msg = "expression is false"
+	}
+
+	t.Log(format.WithCustomMessage(failureMessage+msg, msgAndArgs...))
+}
+
+func failureMsgFromError(err error) string {
+	// Handle errors with non-nil types
+	v := reflect.ValueOf(err)
+	if v.Kind() == reflect.Ptr && v.IsNil() {
+		return fmt.Sprintf("error is not nil: error has type %T", err)
+	}
+	return "error is not nil: " + err.Error()
+}
+
+func boolFailureMessage(expr ast.Expr) (string, error) {
+	if binaryExpr, ok := expr.(*ast.BinaryExpr); ok {
+		x, err := source.FormatNode(binaryExpr.X)
+		if err != nil {
+			return "", err
+		}
+		y, err := source.FormatNode(binaryExpr.Y)
+		if err != nil {
+			return "", err
+		}
+
+		switch binaryExpr.Op {
+		case token.NEQ:
+			return x + " is " + y, nil
+		case token.EQL:
+			return x + " is not " + y, nil
+		case token.GTR:
+			return x + " is <= " + y, nil
+		case token.LSS:
+			return x + " is >= " + y, nil
+		case token.GEQ:
+			return x + " is less than " + y, nil
+		case token.LEQ:
+			return x + " is greater than " + y, nil
+		}
+	}
+
+	if unaryExpr, ok := expr.(*ast.UnaryExpr); ok && unaryExpr.Op == token.NOT {
+		x, err := source.FormatNode(unaryExpr.X)
+		if err != nil {
+			return "", err
+		}
+		return x + " is true", nil
+	}
+
+	if ident, ok := expr.(*ast.Ident); ok {
+		return ident.Name + " is false", nil
+	}
+
+	formatted, err := source.FormatNode(expr)
+	if err != nil {
+		return "", err
+	}
+	return "expression is false: " + formatted, nil
+}

vendor/gotest.tools/v3/internal/assert/result.go

@@ -0,0 +1,146 @@
+package assert
+
+import (
+	"errors"
+	"fmt"
+	"go/ast"
+
+	"gotest.tools/v3/assert/cmp"
+	"gotest.tools/v3/internal/format"
+	"gotest.tools/v3/internal/source"
+)
+
+// RunComparison and return Comparison.Success. If the comparison fails a messages
+// will be printed using t.Log.
+func RunComparison(
+	t LogT,
+	argSelector argSelector,
+	f cmp.Comparison,
+	msgAndArgs ...interface{},
+) bool {
+	if ht, ok := t.(helperT); ok {
+		ht.Helper()
+	}
+	result := f()
+	if result.Success() {
+		return true
+	}
+
+	if source.IsUpdate() {
+		if updater, ok := result.(updateExpected); ok {
+			const stackIndex = 3 // Assert/Check, assert, RunComparison
+			err := updater.UpdatedExpected(stackIndex)
+			switch {
+			case err == nil:
+				return true
+			case errors.Is(err, source.ErrNotFound):
+				// do nothing, fallthrough to regular failure message
+			default:
+				t.Log("failed to update source", err)
+				return false
+			}
+		}
+	}
+
+	var message string
+	switch typed := result.(type) {
+	case resultWithComparisonArgs:
+		const stackIndex = 3 // Assert/Check, assert, RunComparison
+		args, err := source.CallExprArgs(stackIndex)
+		if err != nil {
+			t.Log(err.Error())
+		}
+		message = typed.FailureMessage(filterPrintableExpr(argSelector(args)))
+	case resultBasic:
+		message = typed.FailureMessage()
+	default:
+		message = fmt.Sprintf("comparison returned invalid Result type: %T", result)
+	}
+
+	t.Log(format.WithCustomMessage(failureMessage+message, msgAndArgs...))
+	return false
+}
+
+type resultWithComparisonArgs interface {
+	FailureMessage(args []ast.Expr) string
+}
+
+type resultBasic interface {
+	FailureMessage() string
+}
+
+type updateExpected interface {
+	UpdatedExpected(stackIndex int) error
+}
+
+// filterPrintableExpr filters the ast.Expr slice to only include Expr that are
+// easy to read when printed and contain relevant information to an assertion.
+//
+// Ident and SelectorExpr are included because they print nicely and the variable
+// names may provide additional context to their values.
+// BasicLit and CompositeLit are excluded because their source is equivalent to
+// their value, which is already available.
+// Other types are ignored for now, but could be added if they are relevant.
+func filterPrintableExpr(args []ast.Expr) []ast.Expr {
+	result := make([]ast.Expr, len(args))
+	for i, arg := range args {
+		if isShortPrintableExpr(arg) {
+			result[i] = arg
+			continue
+		}
+
+		if starExpr, ok := arg.(*ast.StarExpr); ok {
+			result[i] = starExpr.X
+			continue
+		}
+	}
+	return result
+}
+
+func isShortPrintableExpr(expr ast.Expr) bool {
+	switch expr.(type) {
+	case *ast.Ident, *ast.SelectorExpr, *ast.IndexExpr, *ast.SliceExpr:
+		return true
+	case *ast.BinaryExpr, *ast.UnaryExpr:
+		return true
+	default:
+		// CallExpr, ParenExpr, TypeAssertExpr, KeyValueExpr, StarExpr
+		return false
+	}
+}
+
+type argSelector func([]ast.Expr) []ast.Expr
+
+// ArgsAfterT selects args starting at position 1. Used when the caller has a
+// testing.T as the first argument, and the args to select should follow it.
+func ArgsAfterT(args []ast.Expr) []ast.Expr {
+	if len(args) < 1 {
+		return nil
+	}
+	return args[1:]
+}
+
+// ArgsFromComparisonCall selects args from the CallExpression at position 1.
+// Used when the caller has a testing.T as the first argument, and the args to
+// select are passed to the cmp.Comparison at position 1.
+func ArgsFromComparisonCall(args []ast.Expr) []ast.Expr {
+	if len(args) <= 1 {
+		return nil
+	}
+	if callExpr, ok := args[1].(*ast.CallExpr); ok {
+		return callExpr.Args
+	}
+	return nil
+}
+
+// ArgsAtZeroIndex selects args from the CallExpression at position 1.
+// Used when the caller accepts a single cmp.Comparison argument.
+func ArgsAtZeroIndex(args []ast.Expr) []ast.Expr {
+	if len(args) == 0 {
+		return nil
+	}
+	if callExpr, ok := args[0].(*ast.CallExpr); ok {
+		return callExpr.Args
+	}
+	return nil
+}

vendor/gotest.tools/v3/internal/cleanup/cleanup.go

@@ -0,0 +1,49 @@
+/*
+Package cleanup handles migration to and support for the Go 1.14+
+testing.TB.Cleanup() function.
+*/
+package cleanup
+
+import (
+	"os"
+	"strings"
+)
+
+type cleanupT interface {
+	Cleanup(f func())
+}
+
+// implemented by gotest.tools/x/subtest.TestContext
+type addCleanupT interface {
+	AddCleanup(f func())
+}
+
+type logT interface {
+	Log(...interface{})
+}
+
+type helperT interface {
+	Helper()
+}
+
+var noCleanup = strings.ToLower(os.Getenv("TEST_NOCLEANUP")) == "true"
+
+// Cleanup registers f as a cleanup function on t if any mechanisms are available.
+//
+// Skips registering f if TEST_NOCLEANUP is set to true.
+func Cleanup(t logT, f func()) {
+	if ht, ok := t.(helperT); ok {
+		ht.Helper()
+	}
+	if noCleanup {
+		t.Log("skipping cleanup because TEST_NOCLEANUP was enabled.")
+		return
+	}
+	if ct, ok := t.(cleanupT); ok {
+		ct.Cleanup(f)
+		return
+	}
+	if tc, ok := t.(addCleanupT); ok {
+		tc.AddCleanup(f)
+	}
+}

vendor/gotest.tools/v3/internal/difflib/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2013, Patrick Mezard
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+    Redistributions in binary form must reproduce the above copyright
+notice, this list of conditions and the following disclaimer in the
+documentation and/or other materials provided with the distribution.
+    The names of its contributors may not be used to endorse or promote
+products derived from this software without specific prior written
+permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
+TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/gotest.tools/v3/internal/difflib/difflib.go

@@ -0,0 +1,427 @@
+/*
+Package difflib is a partial port of Python difflib module.
+
+Original source: https://github.com/pmezard/go-difflib
+
+This file is trimmed to only the parts used by this repository.
+*/
+package difflib // import "gotest.tools/v3/internal/difflib"
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+// Match stores line numbers of size of match
+type Match struct {
+	A    int
+	B    int
+	Size int
+}
+
+// OpCode identifies the type of diff
+type OpCode struct {
+	Tag byte
+	I1  int
+	I2  int
+	J1  int
+	J2  int
+}
+
+// SequenceMatcher compares sequence of strings. The basic
+// algorithm predates, and is a little fancier than, an algorithm
+// published in the late 1980's by Ratcliff and Obershelp under the
+// hyperbolic name "gestalt pattern matching".  The basic idea is to find
+// the longest contiguous matching subsequence that contains no "junk"
+// elements (R-O doesn't address junk).  The same idea is then applied
+// recursively to the pieces of the sequences to the left and to the right
+// of the matching subsequence.  This does not yield minimal edit
+// sequences, but does tend to yield matches that "look right" to people.
+//
+// SequenceMatcher tries to compute a "human-friendly diff" between two
+// sequences.  Unlike e.g. UNIX(tm) diff, the fundamental notion is the
+// longest *contiguous* & junk-free matching subsequence.  That's what
+// catches peoples' eyes.  The Windows(tm) windiff has another interesting
+// notion, pairing up elements that appear uniquely in each sequence.
+// That, and the method here, appear to yield more intuitive difference
+// reports than does diff.  This method appears to be the least vulnerable
+// to synching up on blocks of "junk lines", though (like blank lines in
+// ordinary text files, or maybe "<P>" lines in HTML files).  That may be
+// because this is the only method of the 3 that has a *concept* of
+// "junk" <wink>.
+//
+// Timing:  Basic R-O is cubic time worst case and quadratic time expected
+// case.  SequenceMatcher is quadratic time for the worst case and has
+// expected-case behavior dependent in a complicated way on how many
+// elements the sequences have in common; best case time is linear.
+type SequenceMatcher struct {
+	a              []string
+	b              []string
+	b2j            map[string][]int
+	IsJunk         func(string) bool
+	autoJunk       bool
+	bJunk          map[string]struct{}
+	matchingBlocks []Match
+	fullBCount     map[string]int
+	bPopular       map[string]struct{}
+	opCodes        []OpCode
+}
+
+// NewMatcher returns a new SequenceMatcher
+func NewMatcher(a, b []string) *SequenceMatcher {
+	m := SequenceMatcher{autoJunk: true}
+	m.SetSeqs(a, b)
+	return &m
+}
+
+// SetSeqs sets two sequences to be compared.
+func (m *SequenceMatcher) SetSeqs(a, b []string) {
+	m.SetSeq1(a)
+	m.SetSeq2(b)
+}
+
+// SetSeq1 sets the first sequence to be compared. The second sequence to be compared is
+// not changed.
+//
+// SequenceMatcher computes and caches detailed information about the second
+// sequence, so if you want to compare one sequence S against many sequences,
+// use .SetSeq2(s) once and call .SetSeq1(x) repeatedly for each of the other
+// sequences.
+//
+// See also SetSeqs() and SetSeq2().
+func (m *SequenceMatcher) SetSeq1(a []string) {
+	if &a == &m.a {
+		return
+	}
+	m.a = a
+	m.matchingBlocks = nil
+	m.opCodes = nil
+}
+
+// SetSeq2 sets the second sequence to be compared. The first sequence to be compared is
+// not changed.
+func (m *SequenceMatcher) SetSeq2(b []string) {
+	if &b == &m.b {
+		return
+	}
+	m.b = b
+	m.matchingBlocks = nil
+	m.opCodes = nil
+	m.fullBCount = nil
+	m.chainB()
+}
+
+func (m *SequenceMatcher) chainB() {
+	// Populate line -> index mapping
+	b2j := map[string][]int{}
+	for i, s := range m.b {
+		indices := b2j[s]
+		indices = append(indices, i)
+		b2j[s] = indices
+	}
+
+	// Purge junk elements
+	m.bJunk = map[string]struct{}{}
+	if m.IsJunk != nil {
+		junk := m.bJunk
+		for s := range b2j {
+			if m.IsJunk(s) {
+				junk[s] = struct{}{}
+			}
+		}
+		for s := range junk {
+			delete(b2j, s)
+		}
+	}
+
+	// Purge remaining popular elements
+	popular := map[string]struct{}{}
+	n := len(m.b)
+	if m.autoJunk && n >= 200 {
+		ntest := n/100 + 1
+		for s, indices := range b2j {
+			if len(indices) > ntest {
+				popular[s] = struct{}{}
+			}
+		}
+		for s := range popular {
+			delete(b2j, s)
+		}
+	}
+	m.bPopular = popular
+	m.b2j = b2j
+}
+
+func (m *SequenceMatcher) isBJunk(s string) bool {
+	_, ok := m.bJunk[s]
+	return ok
+}
+
+// Find longest matching block in a[alo:ahi] and b[blo:bhi].
+//
+// If IsJunk is not defined:
+//
+// Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where
+//
+//	alo <= i <= i+k <= ahi
+//	blo <= j <= j+k <= bhi
+//
+// and for all (i',j',k') meeting those conditions,
+//
+//	k >= k'
+//	i <= i'
+//	and if i == i', j <= j'
+//
+// In other words, of all maximal matching blocks, return one that
+// starts earliest in a, and of all those maximal matching blocks that
+// start earliest in a, return the one that starts earliest in b.
+//
+// If IsJunk is defined, first the longest matching block is
+// determined as above, but with the additional restriction that no
+// junk element appears in the block.  Then that block is extended as
+// far as possible by matching (only) junk elements on both sides.  So
+// the resulting block never matches on junk except as identical junk
+// happens to be adjacent to an "interesting" match.
+//
+// If no blocks match, return (alo, blo, 0).
+func (m *SequenceMatcher) findLongestMatch(alo, ahi, blo, bhi int) Match {
+	// CAUTION:  stripping common prefix or suffix would be incorrect.
+	// E.g.,
+	//    ab
+	//    acab
+	// Longest matching block is "ab", but if common prefix is
+	// stripped, it's "a" (tied with "b").  UNIX(tm) diff does so
+	// strip, so ends up claiming that ab is changed to acab by
+	// inserting "ca" in the middle.  That's minimal but unintuitive:
+	// "it's obvious" that someone inserted "ac" at the front.
+	// Windiff ends up at the same place as diff, but by pairing up
+	// the unique 'b's and then matching the first two 'a's.
+	besti, bestj, bestsize := alo, blo, 0
+
+	// find longest junk-free match
+	// during an iteration of the loop, j2len[j] = length of longest
+	// junk-free match ending with a[i-1] and b[j]
+	j2len := map[int]int{}
+	for i := alo; i != ahi; i++ {
+		// look at all instances of a[i] in b; note that because
+		// b2j has no junk keys, the loop is skipped if a[i] is junk
+		newj2len := map[int]int{}
+		for _, j := range m.b2j[m.a[i]] {
+			// a[i] matches b[j]
+			if j < blo {
+				continue
+			}
+			if j >= bhi {
+				break
+			}
+			k := j2len[j-1] + 1
+			newj2len[j] = k
+			if k > bestsize {
+				besti, bestj, bestsize = i-k+1, j-k+1, k
+			}
+		}
+		j2len = newj2len
+	}
+
+	// Extend the best by non-junk elements on each end.  In particular,
+	// "popular" non-junk elements aren't in b2j, which greatly speeds
+	// the inner loop above, but also means "the best" match so far
+	// doesn't contain any junk *or* popular non-junk elements.
+	for besti > alo && bestj > blo && !m.isBJunk(m.b[bestj-1]) &&
+		m.a[besti-1] == m.b[bestj-1] {
+		besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
+	}
+	for besti+bestsize < ahi && bestj+bestsize < bhi &&
+		!m.isBJunk(m.b[bestj+bestsize]) &&
+		m.a[besti+bestsize] == m.b[bestj+bestsize] {
+		bestsize += 1
+	}
+
+	// Now that we have a wholly interesting match (albeit possibly
+	// empty!), we may as well suck up the matching junk on each
+	// side of it too.  Can't think of a good reason not to, and it
+	// saves post-processing the (possibly considerable) expense of
+	// figuring out what to do with it.  In the case of an empty
+	// interesting match, this is clearly the right thing to do,
+	// because no other kind of match is possible in the regions.
+	for besti > alo && bestj > blo && m.isBJunk(m.b[bestj-1]) &&
+		m.a[besti-1] == m.b[bestj-1] {
+		besti, bestj, bestsize = besti-1, bestj-1, bestsize+1
+	}
+	for besti+bestsize < ahi && bestj+bestsize < bhi &&
+		m.isBJunk(m.b[bestj+bestsize]) &&
+		m.a[besti+bestsize] == m.b[bestj+bestsize] {
+		bestsize += 1
+	}
+
+	return Match{A: besti, B: bestj, Size: bestsize}
+}
+
+// GetMatchingBlocks returns a list of triples describing matching subsequences.
+//
+// Each triple is of the form (i, j, n), and means that
+// a[i:i+n] == b[j:j+n].  The triples are monotonically increasing in
+// i and in j. It's also guaranteed that if (i, j, n) and (i', j', n') are
+// adjacent triples in the list, and the second is not the last triple in the
+// list, then i+n != i' or j+n != j'. IOW, adjacent triples never describe
+// adjacent equal blocks.
+//
+// The last triple is a dummy, (len(a), len(b), 0), and is the only
+// triple with n==0.
+func (m *SequenceMatcher) GetMatchingBlocks() []Match {
+	if m.matchingBlocks != nil {
+		return m.matchingBlocks
+	}
+
+	var matchBlocks func(alo, ahi, blo, bhi int, matched []Match) []Match
+	matchBlocks = func(alo, ahi, blo, bhi int, matched []Match) []Match {
+		match := m.findLongestMatch(alo, ahi, blo, bhi)
+		i, j, k := match.A, match.B, match.Size
+		if match.Size > 0 {
+			if alo < i && blo < j {
+				matched = matchBlocks(alo, i, blo, j, matched)
+			}
+			matched = append(matched, match)
+			if i+k < ahi && j+k < bhi {
+				matched = matchBlocks(i+k, ahi, j+k, bhi, matched)
+			}
+		}
+		return matched
+	}
+	matched := matchBlocks(0, len(m.a), 0, len(m.b), nil)
+
+	// It's possible that we have adjacent equal blocks in the
+	// matching_blocks list now.
+	nonAdjacent := []Match{}
+	i1, j1, k1 := 0, 0, 0
+	for _, b := range matched {
+		// Is this block adjacent to i1, j1, k1?
+		i2, j2, k2 := b.A, b.B, b.Size
+		if i1+k1 == i2 && j1+k1 == j2 {
+			// Yes, so collapse them -- this just increases the length of
+			// the first block by the length of the second, and the first
+			// block so lengthened remains the block to compare against.
+			k1 += k2
+		} else {
+			// Not adjacent.  Remember the first block (k1==0 means it's
+			// the dummy we started with), and make the second block the
+			// new block to compare against.
+			if k1 > 0 {
+				nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
+			}
+			i1, j1, k1 = i2, j2, k2
+		}
+	}
+	if k1 > 0 {
+		nonAdjacent = append(nonAdjacent, Match{i1, j1, k1})
+	}
+
+	nonAdjacent = append(nonAdjacent, Match{len(m.a), len(m.b), 0})
+	m.matchingBlocks = nonAdjacent
+	return m.matchingBlocks
+}
+
+// GetOpCodes returns a list of 5-tuples describing how to turn a into b.
+//
+// Each tuple is of the form (tag, i1, i2, j1, j2).  The first tuple
+// has i1 == j1 == 0, and remaining tuples have i1 == the i2 from the
+// tuple preceding it, and likewise for j1 == the previous j2.
+//
+// The tags are characters, with these meanings:
+//
+// 'r' (replace):  a[i1:i2] should be replaced by b[j1:j2]
+//
+// 'd' (delete):   a[i1:i2] should be deleted, j1==j2 in this case.
+//
+// 'i' (insert):   b[j1:j2] should be inserted at a[i1:i1], i1==i2 in this case.
+//
+// 'e' (equal):    a[i1:i2] == b[j1:j2]
+func (m *SequenceMatcher) GetOpCodes() []OpCode {
+	if m.opCodes != nil {
+		return m.opCodes
+	}
+	i, j := 0, 0
+	matching := m.GetMatchingBlocks()
+	opCodes := make([]OpCode, 0, len(matching))
+	for _, m := range matching {
+		//  invariant:  we've pumped out correct diffs to change
+		//  a[:i] into b[:j], and the next matching block is
+		//  a[ai:ai+size] == b[bj:bj+size]. So we need to pump
+		//  out a diff to change a[i:ai] into b[j:bj], pump out
+		//  the matching block, and move (i,j) beyond the match
+		ai, bj, size := m.A, m.B, m.Size
+		tag := byte(0)
+		if i < ai && j < bj {
+			tag = 'r'
+		} else if i < ai {
+			tag = 'd'
+		} else if j < bj {
+			tag = 'i'
+		}
+		if tag > 0 {
+			opCodes = append(opCodes, OpCode{tag, i, ai, j, bj})
+		}
+		i, j = ai+size, bj+size
+		// the list of matching blocks is terminated by a
+		// sentinel with size 0
+		if size > 0 {
+			opCodes = append(opCodes, OpCode{'e', ai, i, bj, j})
+		}
+	}
+	m.opCodes = opCodes
+	return m.opCodes
+}
+
+// GetGroupedOpCodes isolates change clusters by eliminating ranges with no changes.
+//
+// Return a generator of groups with up to n lines of context.
+// Each group is in the same format as returned by GetOpCodes().
+func (m *SequenceMatcher) GetGroupedOpCodes(n int) [][]OpCode {
+	if n < 0 {
+		n = 3
+	}
+	codes := m.GetOpCodes()
+	if len(codes) == 0 {
+		codes = []OpCode{{'e', 0, 1, 0, 1}}
+	}
+	// Fixup leading and trailing groups if they show no changes.
+	if codes[0].Tag == 'e' {
+		c := codes[0]
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		codes[0] = OpCode{c.Tag, max(i1, i2-n), i2, max(j1, j2-n), j2}
+	}
+	if codes[len(codes)-1].Tag == 'e' {
+		c := codes[len(codes)-1]
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		codes[len(codes)-1] = OpCode{c.Tag, i1, min(i2, i1+n), j1, min(j2, j1+n)}
+	}
+	nn := n + n
+	groups := [][]OpCode{}
+	group := []OpCode{}
+	for _, c := range codes {
+		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
+		// End the current group and start a new one whenever
+		// there is a large range with no changes.
+		if c.Tag == 'e' && i2-i1 > nn {
+			group = append(group, OpCode{c.Tag, i1, min(i2, i1+n),
+				j1, min(j2, j1+n)})
+			groups = append(groups, group)
+			group = []OpCode{}
+			i1, j1 = max(i1, i2-n), max(j1, j2-n)
+		}
+		group = append(group, OpCode{c.Tag, i1, i2, j1, j2})
+	}
+	if len(group) > 0 && !(len(group) == 1 && group[0].Tag == 'e') {
+		groups = append(groups, group)
+	}
+	return groups
+}

vendor/gotest.tools/v3/internal/format/diff.go

@@ -0,0 +1,162 @@
+// Package format provides utilities for formatting diffs and messages.
+package format
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+	"unicode"
+
+	"gotest.tools/v3/internal/difflib"
+)
+
+const (
+	contextLines = 2
+)
+
+// DiffConfig for a unified diff
+type DiffConfig struct {
+	A    string
+	B    string
+	From string
+	To   string
+}
+
+// UnifiedDiff is a modified version of difflib.WriteUnifiedDiff with better
+// support for showing the whitespace differences.
+func UnifiedDiff(conf DiffConfig) string {
+	a := strings.SplitAfter(conf.A, "\n")
+	b := strings.SplitAfter(conf.B, "\n")
+	groups := difflib.NewMatcher(a, b).GetGroupedOpCodes(contextLines)
+	if len(groups) == 0 {
+		return ""
+	}
+
+	buf := new(bytes.Buffer)
+	writeFormat := func(format string, args ...interface{}) {
+		buf.WriteString(fmt.Sprintf(format, args...))
+	}
+	writeLine := func(prefix string, s string) {
+		buf.WriteString(prefix + s)
+	}
+	if hasWhitespaceDiffLines(groups, a, b) {
+		writeLine = visibleWhitespaceLine(writeLine)
+	}
+	formatHeader(writeFormat, conf)
+	for _, group := range groups {
+		formatRangeLine(writeFormat, group)
+		for _, opCode := range group {
+			in, out := a[opCode.I1:opCode.I2], b[opCode.J1:opCode.J2]
+			switch opCode.Tag {
+			case 'e':
+				formatLines(writeLine, " ", in)
+			case 'r':
+				formatLines(writeLine, "-", in)
+				formatLines(writeLine, "+", out)
+			case 'd':
+				formatLines(writeLine, "-", in)
+			case 'i':
+				formatLines(writeLine, "+", out)
+			}
+		}
+	}
+	return buf.String()
+}
+
+// hasWhitespaceDiffLines returns true if any diff groups is only different
+// because of whitespace characters.
+func hasWhitespaceDiffLines(groups [][]difflib.OpCode, a, b []string) bool {
+	for _, group := range groups {
+		in, out := new(bytes.Buffer), new(bytes.Buffer)
+		for _, opCode := range group {
+			if opCode.Tag == 'e' {
+				continue
+			}
+			for _, line := range a[opCode.I1:opCode.I2] {
+				in.WriteString(line)
+			}
+			for _, line := range b[opCode.J1:opCode.J2] {
+				out.WriteString(line)
+			}
+		}
+		if removeWhitespace(in.String()) == removeWhitespace(out.String()) {
+			return true
+		}
+	}
+	return false
+}
+
+func removeWhitespace(s string) string {
+	var result []rune
+	for _, r := range s {
+		if !unicode.IsSpace(r) {
+			result = append(result, r)
+		}
+	}
+	return string(result)
+}
+
+func visibleWhitespaceLine(ws func(string, string)) func(string, string) {
+	mapToVisibleSpace := func(r rune) rune {
+		switch r {
+		case '\n':
+		case ' ':
+			return '·'
+		case '\t':
+			return '▷'
+		case '\v':
+			return '▽'
+		case '\r':
+			return '↵'
+		case '\f':
+			return '↓'
+		default:
+			if unicode.IsSpace(r) {
+				return '<27>'
+			}
+		}
+		return r
+	}
+	return func(prefix, s string) {
+		ws(prefix, strings.Map(mapToVisibleSpace, s))
+	}
+}
+
+func formatHeader(wf func(string, ...interface{}), conf DiffConfig) {
+	if conf.From != "" || conf.To != "" {
+		wf("--- %s\n", conf.From)
+		wf("+++ %s\n", conf.To)
+	}
+}
+
+func formatRangeLine(wf func(string, ...interface{}), group []difflib.OpCode) {
+	first, last := group[0], group[len(group)-1]
+	range1 := formatRangeUnified(first.I1, last.I2)
+	range2 := formatRangeUnified(first.J1, last.J2)
+	wf("@@ -%s +%s @@\n", range1, range2)
+}
+
+// Convert range to the "ed" format
+func formatRangeUnified(start, stop int) string {
+	// Per the diff spec at http://www.unix.org/single_unix_specification/
+	beginning := start + 1 // lines start numbering with one
+	length := stop - start
+	if length == 1 {
+		return fmt.Sprintf("%d", beginning)
+	}
+	if length == 0 {
+		beginning-- // empty ranges begin at line just before the range
+	}
+	return fmt.Sprintf("%d,%d", beginning, length)
+}
+
+func formatLines(writeLine func(string, string), prefix string, lines []string) {
+	for _, line := range lines {
+		writeLine(prefix, line)
+	}
+	// Add a newline if the last line is missing one so that the diff displays
+	// properly.
+	if !strings.HasSuffix(lines[len(lines)-1], "\n") {
+		writeLine("", "\n")
+	}
+}

vendor/gotest.tools/v3/internal/format/format.go

@@ -0,0 +1,27 @@
+package format // import "gotest.tools/v3/internal/format"
+
+import "fmt"
+
+// Message accepts a msgAndArgs varargs and formats it using fmt.Sprintf
+func Message(msgAndArgs ...interface{}) string {
+	switch len(msgAndArgs) {
+	case 0:
+		return ""
+	case 1:
+		return fmt.Sprintf("%v", msgAndArgs[0])
+	default:
+		return fmt.Sprintf(msgAndArgs[0].(string), msgAndArgs[1:]...)
+	}
+}
+
+// WithCustomMessage accepts one or two messages and formats them appropriately
+func WithCustomMessage(source string, msgAndArgs ...interface{}) string {
+	custom := Message(msgAndArgs...)
+	switch {
+	case custom == "":
+		return source
+	case source == "":
+		return custom
+	}
+	return fmt.Sprintf("%s: %s", source, custom)
+}

vendor/gotest.tools/v3/internal/source/defers.go

@@ -0,0 +1,52 @@
+package source
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+)
+
+func scanToDeferLine(fileset *token.FileSet, node ast.Node, lineNum int) ast.Node {
+	var matchedNode ast.Node
+	ast.Inspect(node, func(node ast.Node) bool {
+		switch {
+		case node == nil || matchedNode != nil:
+			return false
+		case fileset.Position(node.End()).Line == lineNum:
+			if funcLit, ok := node.(*ast.FuncLit); ok {
+				matchedNode = funcLit
+				return false
+			}
+		}
+		return true
+	})
+	debug("defer line node: %s", debugFormatNode{matchedNode})
+	return matchedNode
+}
+
+func guessDefer(node ast.Node) (ast.Node, error) {
+	defers := collectDefers(node)
+	switch len(defers) {
+	case 0:
+		return nil, fmt.Errorf("failed to find expression in defer")
+	case 1:
+		return defers[0].Call, nil
+	default:
+		return nil, fmt.Errorf(
+			"ambiguous call expression: multiple (%d) defers in call block",
+			len(defers))
+	}
+}
+
+func collectDefers(node ast.Node) []*ast.DeferStmt {
+	var defers []*ast.DeferStmt
+	ast.Inspect(node, func(node ast.Node) bool {
+		if d, ok := node.(*ast.DeferStmt); ok {
+			defers = append(defers, d)
+			debug("defer: %s", debugFormatNode{d})
+			return false
+		}
+		return true
+	})
+	return defers
+}

vendor/gotest.tools/v3/internal/source/source.go

@@ -0,0 +1,148 @@
+// Package source provides utilities for handling source-code.
+package source // import "gotest.tools/v3/internal/source"
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"go/ast"
+	"go/format"
+	"go/parser"
+	"go/token"
+	"os"
+	"runtime"
+)
+
+// FormattedCallExprArg returns the argument from an ast.CallExpr at the
+// index in the call stack. The argument is formatted using FormatNode.
+func FormattedCallExprArg(stackIndex int, argPos int) (string, error) {
+	args, err := CallExprArgs(stackIndex + 1)
+	if err != nil {
+		return "", err
+	}
+	if argPos >= len(args) {
+		return "", errors.New("failed to find expression")
+	}
+	return FormatNode(args[argPos])
+}
+
+// CallExprArgs returns the ast.Expr slice for the args of an ast.CallExpr at
+// the index in the call stack.
+func CallExprArgs(stackIndex int) ([]ast.Expr, error) {
+	_, filename, line, ok := runtime.Caller(stackIndex + 1)
+	if !ok {
+		return nil, errors.New("failed to get call stack")
+	}
+	debug("call stack position: %s:%d", filename, line)
+
+	fileset := token.NewFileSet()
+	astFile, err := parser.ParseFile(fileset, filename, nil, parser.AllErrors)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse source file %s: %w", filename, err)
+	}
+
+	expr, err := getCallExprArgs(fileset, astFile, line)
+	if err != nil {
+		return nil, fmt.Errorf("call from %s:%d: %w", filename, line, err)
+	}
+	return expr, nil
+}
+
+func getNodeAtLine(fileset *token.FileSet, astFile ast.Node, lineNum int) (ast.Node, error) {
+	if node := scanToLine(fileset, astFile, lineNum); node != nil {
+		return node, nil
+	}
+	if node := scanToDeferLine(fileset, astFile, lineNum); node != nil {
+		node, err := guessDefer(node)
+		if err != nil || node != nil {
+			return node, err
+		}
+	}
+	return nil, nil
+}
+
+func scanToLine(fileset *token.FileSet, node ast.Node, lineNum int) ast.Node {
+	var matchedNode ast.Node
+	ast.Inspect(node, func(node ast.Node) bool {
+		switch {
+		case node == nil || matchedNode != nil:
+			return false
+		case fileset.Position(node.Pos()).Line == lineNum:
+			matchedNode = node
+			return false
+		}
+		return true
+	})
+	return matchedNode
+}
+
+func getCallExprArgs(fileset *token.FileSet, astFile ast.Node, line int) ([]ast.Expr, error) {
+	node, err := getNodeAtLine(fileset, astFile, line)
+	switch {
+	case err != nil:
+		return nil, err
+	case node == nil:
+		return nil, fmt.Errorf("failed to find an expression")
+	}
+
+	debug("found node: %s", debugFormatNode{node})
+
+	visitor := &callExprVisitor{}
+	ast.Walk(visitor, node)
+	if visitor.expr == nil {
+		return nil, errors.New("failed to find call expression")
+	}
+	debug("callExpr: %s", debugFormatNode{visitor.expr})
+	return visitor.expr.Args, nil
+}
+
+type callExprVisitor struct {
+	expr *ast.CallExpr
+}
+
+func (v *callExprVisitor) Visit(node ast.Node) ast.Visitor {
+	if v.expr != nil || node == nil {
+		return nil
+	}
+	debug("visit: %s", debugFormatNode{node})
+
+	switch typed := node.(type) {
+	case *ast.CallExpr:
+		v.expr = typed
+		return nil
+	case *ast.DeferStmt:
+		ast.Walk(v, typed.Call.Fun)
+		return nil
+	}
+	return v
+}
+
+// FormatNode using go/format.Node and return the result as a string
+func FormatNode(node ast.Node) (string, error) {
+	buf := new(bytes.Buffer)
+	err := format.Node(buf, token.NewFileSet(), node)
+	return buf.String(), err
+}
+
+var debugEnabled = os.Getenv("GOTESTTOOLS_DEBUG") != ""
+
+func debug(format string, args ...interface{}) {
+	if debugEnabled {
+		fmt.Fprintf(os.Stderr, "DEBUG: "+format+"\n", args...)
+	}
+}
+
+type debugFormatNode struct {
+	ast.Node
+}
+
+func (n debugFormatNode) String() string {
+	if n.Node == nil {
+		return "none"
+	}
+	out, err := FormatNode(n.Node)
+	if err != nil {
+		return fmt.Sprintf("failed to format %s: %s", n.Node, err)
+	}
+	return fmt.Sprintf("(%T) %s", n.Node, out)
+}

vendor/gotest.tools/v3/internal/source/update.go

@@ -0,0 +1,171 @@
+package source
+
+import (
+	"bytes"
+	"errors"
+	"flag"
+	"fmt"
+	"go/ast"
+	"go/format"
+	"go/parser"
+	"go/token"
+	"os"
+	"runtime"
+	"strings"
+)
+
+// IsUpdate is returns true if the -update flag is set. It indicates the user
+// running the tests would like to update any golden values.
+func IsUpdate() bool {
+	if Update {
+		return true
+	}
+	return flag.Lookup("update").Value.(flag.Getter).Get().(bool)
+}
+
+// Update is a shim for testing, and for compatibility with the old -update-golden
+// flag.
+var Update bool
+
+func init() {
+	if f := flag.Lookup("update"); f != nil {
+		getter, ok := f.Value.(flag.Getter)
+		msg := "some other package defined an incompatible -update flag, expected a flag.Bool"
+		if !ok {
+			panic(msg)
+		}
+		if _, ok := getter.Get().(bool); !ok {
+			panic(msg)
+		}
+		return
+	}
+	flag.Bool("update", false, "update golden values")
+}
+
+// ErrNotFound indicates that UpdateExpectedValue failed to find the
+// variable to update, likely because it is not a package level variable.
+var ErrNotFound = fmt.Errorf("failed to find variable for update of golden value")
+
+// UpdateExpectedValue looks for a package-level variable with a name that
+// starts with expected in the arguments to the caller. If the variable is
+// found, the value of the variable will be updated to value of the other
+// argument to the caller.
+func UpdateExpectedValue(stackIndex int, x, y interface{}) error {
+	_, filename, line, ok := runtime.Caller(stackIndex + 1)
+	if !ok {
+		return errors.New("failed to get call stack")
+	}
+	debug("call stack position: %s:%d", filename, line)
+
+	fileset := token.NewFileSet()
+	astFile, err := parser.ParseFile(fileset, filename, nil, parser.AllErrors|parser.ParseComments)
+	if err != nil {
+		return fmt.Errorf("failed to parse source file %s: %w", filename, err)
+	}
+
+	expr, err := getCallExprArgs(fileset, astFile, line)
+	if err != nil {
+		return fmt.Errorf("call from %s:%d: %w", filename, line, err)
+	}
+
+	if len(expr) < 3 {
+		debug("not enough arguments %d: %v",
+			len(expr), debugFormatNode{Node: &ast.CallExpr{Args: expr}})
+		return ErrNotFound
+	}
+
+	argIndex, ident := getIdentForExpectedValueArg(expr)
+	if argIndex < 0 || ident == nil {
+		debug("no arguments started with the word 'expected': %v",
+			debugFormatNode{Node: &ast.CallExpr{Args: expr}})
+		return ErrNotFound
+	}
+
+	value := x
+	if argIndex == 1 {
+		value = y
+	}
+
+	strValue, ok := value.(string)
+	if !ok {
+		debug("value must be type string, got %T", value)
+		return ErrNotFound
+	}
+	return UpdateVariable(filename, fileset, astFile, ident, strValue)
+}
+
+// UpdateVariable writes to filename the contents of astFile with the value of
+// the variable updated to value.
+func UpdateVariable(
+	filename string,
+	fileset *token.FileSet,
+	astFile *ast.File,
+	ident *ast.Ident,
+	value string,
+) error {
+	obj := ident.Obj
+	if obj == nil {
+		return ErrNotFound
+	}
+	if obj.Kind != ast.Con && obj.Kind != ast.Var {
+		debug("can only update var and const, found %v", obj.Kind)
+		return ErrNotFound
+	}
+
+	switch decl := obj.Decl.(type) {
+	case *ast.ValueSpec:
+		if len(decl.Names) != 1 {
+			debug("more than one name in ast.ValueSpec")
+			return ErrNotFound
+		}
+
+		decl.Values[0] = &ast.BasicLit{
+			Kind:  token.STRING,
+			Value: "`" + value + "`",
+		}
+
+	case *ast.AssignStmt:
+		if len(decl.Lhs) != 1 {
+			debug("more than one name in ast.AssignStmt")
+			return ErrNotFound
+		}
+
+		decl.Rhs[0] = &ast.BasicLit{
+			Kind:  token.STRING,
+			Value: "`" + value + "`",
+		}
+
+	default:
+		debug("can only update *ast.ValueSpec, found %T", obj.Decl)
+		return ErrNotFound
+	}
+
+	var buf bytes.Buffer
+	if err := format.Node(&buf, fileset, astFile); err != nil {
+		return fmt.Errorf("failed to format file after update: %w", err)
+	}
+
+	fh, err := os.Create(filename)
+	if err != nil {
+		return fmt.Errorf("failed to open file %v: %w", filename, err)
+	}
+	if _, err = fh.Write(buf.Bytes()); err != nil {
+		return fmt.Errorf("failed to write file %v: %w", filename, err)
+	}
+	if err := fh.Sync(); err != nil {
+		return fmt.Errorf("failed to sync file %v: %w", filename, err)
+	}
+	return nil
+}
+
+func getIdentForExpectedValueArg(expr []ast.Expr) (int, *ast.Ident) {
+	for i := 1; i < 3; i++ {
+		switch e := expr[i].(type) {
+		case *ast.Ident:
+			if strings.HasPrefix(strings.ToLower(e.Name), "expected") {
+				return i, e
+			}
+		}
+	}
+	return -1, nil
+}

vendor/gotest.tools/v3/internal/source/version.go

@@ -0,0 +1,35 @@
+package source
+
+import (
+	"runtime"
+	"strconv"
+	"strings"
+)
+
+// GoVersionLessThan returns true if runtime.Version() is semantically less than
+// version major.minor. Returns false if a release version can not be parsed from
+// runtime.Version().
+func GoVersionLessThan(major, minor int64) bool {
+	version := runtime.Version()
+	// not a release version
+	if !strings.HasPrefix(version, "go") {
+		return false
+	}
+	version = strings.TrimPrefix(version, "go")
+	parts := strings.Split(version, ".")
+	if len(parts) < 2 {
+		return false
+	}
+	rMajor, err := strconv.ParseInt(parts[0], 10, 32)
+	if err != nil {
+		return false
+	}
+	if rMajor != major {
+		return rMajor < major
+	}
+	rMinor, err := strconv.ParseInt(parts[1], 10, 32)
+	if err != nil {
+		return false
+	}
+	return rMinor < minor
+}