identity: more cleaning and fixes after a code review

5 files changed, 0 insertions, 798 deletions

diff --git a/vendor/gotest.tools/internal/difflib/LICENSE b/vendor/gotest.tools/internal/difflib/LICENSE
deleted file mode 100644
index c67dad61..00000000
--- a/vendor/gotest.tools/internal/difflib/LICENSE
+++ /dev/null
@@ -1,27 +0,0 @@
-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.
diff --git a/vendor/gotest.tools/internal/difflib/difflib.go b/vendor/gotest.tools/internal/difflib/difflib.go
deleted file mode 100644
index 5efa99c1..00000000
--- a/vendor/gotest.tools/internal/difflib/difflib.go
+++ /dev/null
@@ -1,420 +0,0 @@
-/* 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/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
-}
-
-type Match struct {
-	A    int
-	B    int
-	Size int
-}
-
-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
-}
-
-func NewMatcher(a, b []string) *SequenceMatcher {
-	m := SequenceMatcher{autoJunk: true}
-	m.SetSeqs(a, b)
-	return &m
-}
-
-// Set two sequences to be compared.
-func (m *SequenceMatcher) SetSeqs(a, b []string) {
-	m.SetSeq1(a)
-	m.SetSeq2(b)
-}
-
-// Set 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
-}
-
-// Set 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}
-}
-
-// Return 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
-}
-
-// Return 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
-}
-
-// Isolate 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{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
-}
diff --git a/vendor/gotest.tools/internal/format/diff.go b/vendor/gotest.tools/internal/format/diff.go
deleted file mode 100644
index c938c97b..00000000
--- a/vendor/gotest.tools/internal/format/diff.go
+++ /dev/null
@@ -1,161 +0,0 @@
-package format
-
-import (
-	"bytes"
-	"fmt"
-	"strings"
-	"unicode"
-
-	"gotest.tools/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 '�'
-			}
-		}
-		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")
-	}
-}
diff --git a/vendor/gotest.tools/internal/format/format.go b/vendor/gotest.tools/internal/format/format.go
deleted file mode 100644
index 8f6494f9..00000000
--- a/vendor/gotest.tools/internal/format/format.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package format // import "gotest.tools/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)
-}
diff --git a/vendor/gotest.tools/internal/source/source.go b/vendor/gotest.tools/internal/source/source.go
deleted file mode 100644
index a05933cc..00000000
--- a/vendor/gotest.tools/internal/source/source.go
+++ /dev/null
@@ -1,163 +0,0 @@
-package source // import "gotest.tools/internal/source"
-
-import (
-	"bytes"
-	"fmt"
-	"go/ast"
-	"go/format"
-	"go/parser"
-	"go/token"
-	"os"
-	"runtime"
-	"strconv"
-	"strings"
-
-	"github.com/pkg/errors"
-)
-
-const baseStackIndex = 1
-
-// 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
-	}
-	return FormatNode(args[argPos])
-}
-
-func getNodeAtLine(filename string, lineNum int) (ast.Node, error) {
-	fileset := token.NewFileSet()
-	astFile, err := parser.ParseFile(fileset, filename, nil, parser.AllErrors)
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to parse source file: %s", filename)
-	}
-
-	node := scanToLine(fileset, astFile, lineNum)
-	if node == nil {
-		return nil, errors.Errorf(
-			"failed to find an expression on line %d in %s", lineNum, filename)
-	}
-	return node, nil
-}
-
-func scanToLine(fileset *token.FileSet, node ast.Node, lineNum int) ast.Node {
-	v := &scanToLineVisitor{lineNum: lineNum, fileset: fileset}
-	ast.Walk(v, node)
-	return v.matchedNode
-}
-
-type scanToLineVisitor struct {
-	lineNum     int
-	matchedNode ast.Node
-	fileset     *token.FileSet
-}
-
-func (v *scanToLineVisitor) Visit(node ast.Node) ast.Visitor {
-	if node == nil || v.matchedNode != nil {
-		return nil
-	}
-	if v.nodePosition(node).Line == v.lineNum {
-		v.matchedNode = node
-		return nil
-	}
-	return v
-}
-
-// In golang 1.9 the line number changed from being the line where the statement
-// ended to the line where the statement began.
-func (v *scanToLineVisitor) nodePosition(node ast.Node) token.Position {
-	if goVersionBefore19 {
-		return v.fileset.Position(node.End())
-	}
-	return v.fileset.Position(node.Pos())
-}
-
-var goVersionBefore19 = isGOVersionBefore19()
-
-func isGOVersionBefore19() 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
-	}
-	minor, err := strconv.ParseInt(parts[1], 10, 32)
-	return err == nil && parts[0] == "1" && minor < 9
-}
-
-func getCallExprArgs(node ast.Node) ([]ast.Expr, error) {
-	visitor := &callExprVisitor{}
-	ast.Walk(visitor, node)
-	if visitor.expr == nil {
-		return nil, errors.New("failed to find call expression")
-	}
-	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 (%T): %s", node, debugFormatNode{node})
-
-	if callExpr, ok := node.(*ast.CallExpr); ok {
-		v.expr = callExpr
-		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
-}
-
-// 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, lineNum, ok := runtime.Caller(baseStackIndex + stackIndex)
-	if !ok {
-		return nil, errors.New("failed to get call stack")
-	}
-	debug("call stack position: %s:%d", filename, lineNum)
-
-	node, err := getNodeAtLine(filename, lineNum)
-	if err != nil {
-		return nil, err
-	}
-	debug("found node (%T): %s", node, debugFormatNode{node})
-
-	return getCallExprArgs(node)
-}
-
-var debugEnabled = os.Getenv("GOTESTYOURSELF_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 {
-	out, err := FormatNode(n.Node)
-	if err != nil {
-		return fmt.Sprintf("failed to format %s: %s", n.Node, err)
-	}
-	return out
-}