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go/internal/span/utf16_test.go
Paul Jolly 72ffa07ba3 internal/span: handle character values beyond end of line in FromUTF16Column
On the assumption these implementations are designed to
support/implement the LSP spec, FromUTF16Column should handle the case
where a character value is beyond the end of the line.

https://github.com/Microsoft/language-server-protocol/blob/gh-pages/specification.md#position:

> * If the character value is greater than the line length it defaults back to the
> * line length.

Fixes golang/go#31883

Change-Id: I370845b7f2f046d8e84048a26bae5b23e9c27d06
Reviewed-on: https://go-review.googlesource.com/c/tools/+/185058
Run-TryBot: Paul Jolly <paul@myitcv.org.uk>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
2019-07-06 07:08:13 +00:00

323 lines
8.2 KiB
Go

// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package span_test
import (
"strings"
"testing"
"golang.org/x/tools/internal/span"
)
// The funny character below is 4 bytes long in UTF-8; two UTF-16 code points
var funnyString = []byte("𐐀23\n𐐀45")
var toUTF16Tests = []struct {
scenario string
input []byte
line int // 1-indexed count
col int // 1-indexed byte position in line
offset int // 0-indexed byte offset into input
resUTF16col int // 1-indexed UTF-16 col number
pre string // everything before the cursor on the line
post string // everything from the cursor onwards
err string // expected error string in call to ToUTF16Column
issue *bool
}{
{
scenario: "cursor missing content",
input: nil,
err: "ToUTF16Column: missing content",
},
{
scenario: "cursor missing position",
input: funnyString,
line: -1,
col: -1,
err: "ToUTF16Column: point is missing position",
},
{
scenario: "cursor missing offset",
input: funnyString,
line: 1,
col: 1,
offset: -1,
err: "ToUTF16Column: point is missing offset",
},
{
scenario: "zero length input; cursor at first col, first line",
input: []byte(""),
line: 1,
col: 1,
offset: 0,
resUTF16col: 1,
},
{
scenario: "cursor before funny character; first line",
input: funnyString,
line: 1,
col: 1,
offset: 0,
resUTF16col: 1,
pre: "",
post: "𐐀23",
},
{
scenario: "cursor after funny character; first line",
input: funnyString,
line: 1,
col: 5, // 4 + 1 (1-indexed)
offset: 4,
resUTF16col: 3, // 2 + 1 (1-indexed)
pre: "𐐀",
post: "23",
},
{
scenario: "cursor after last character on first line",
input: funnyString,
line: 1,
col: 7, // 4 + 1 + 1 + 1 (1-indexed)
offset: 6, // 4 + 1 + 1
resUTF16col: 5, // 2 + 1 + 1 + 1 (1-indexed)
pre: "𐐀23",
post: "",
},
{
scenario: "cursor before funny character; second line",
input: funnyString,
line: 2,
col: 1,
offset: 7, // length of first line
resUTF16col: 1,
pre: "",
post: "𐐀45",
},
{
scenario: "cursor after funny character; second line",
input: funnyString,
line: 1,
col: 5, // 4 + 1 (1-indexed)
offset: 11, // 7 (length of first line) + 4
resUTF16col: 3, // 2 + 1 (1-indexed)
pre: "𐐀",
post: "45",
},
{
scenario: "cursor after last character on second line",
input: funnyString,
line: 2,
col: 7, // 4 + 1 + 1 + 1 (1-indexed)
offset: 13, // 7 (length of first line) + 4 + 1 + 1
resUTF16col: 5, // 2 + 1 + 1 + 1 (1-indexed)
pre: "𐐀45",
post: "",
},
{
scenario: "cursor beyond end of file",
input: funnyString,
line: 2,
col: 8, // 4 + 1 + 1 + 1 + 1 (1-indexed)
offset: 14, // 4 + 1 + 1 + 1
err: "ToUTF16Column: offsets 7-14 outside file contents (13)",
},
}
var fromUTF16Tests = []struct {
scenario string
input []byte
line int // 1-indexed line number (isn't actually used)
offset int // 0-indexed byte offset to beginning of line
utf16col int // 1-indexed UTF-16 col number
resCol int // 1-indexed byte position in line
resOffset int // 0-indexed byte offset into input
pre string // everything before the cursor on the line
post string // everything from the cursor onwards
err string // expected error string in call to ToUTF16Column
}{
{
scenario: "zero length input; cursor at first col, first line",
input: []byte(""),
line: 1,
offset: 0,
utf16col: 1,
resCol: 1,
resOffset: 0,
pre: "",
post: "",
},
{
scenario: "missing offset",
input: funnyString,
line: 1,
offset: -1,
err: "FromUTF16Column: point is missing offset",
},
{
scenario: "cursor before funny character",
input: funnyString,
line: 1,
utf16col: 1,
resCol: 1,
resOffset: 0,
pre: "",
post: "𐐀23",
},
{
scenario: "cursor after funny character",
input: funnyString,
line: 1,
utf16col: 3,
resCol: 5,
resOffset: 4,
pre: "𐐀",
post: "23",
},
{
scenario: "cursor after last character on line",
input: funnyString,
line: 1,
utf16col: 5,
resCol: 7,
resOffset: 6,
pre: "𐐀23",
post: "",
},
{
scenario: "cursor beyond last character on line",
input: funnyString,
line: 1,
offset: 0,
utf16col: 6,
resCol: 7,
resOffset: 6,
pre: "𐐀23",
post: "",
},
{
scenario: "cursor before funny character; second line",
input: funnyString,
line: 2,
offset: 7, // length of first line
utf16col: 1,
resCol: 1,
resOffset: 7,
pre: "",
post: "𐐀45",
},
{
scenario: "cursor after funny character; second line",
input: funnyString,
line: 2,
offset: 7, // length of first line
utf16col: 3, // 2 + 1 (1-indexed)
resCol: 5, // 4 + 1 (1-indexed)
resOffset: 11, // 7 (length of first line) + 4
pre: "𐐀",
post: "45",
},
{
scenario: "cursor after last character on second line",
input: funnyString,
line: 2,
offset: 7, // length of first line
utf16col: 5, // 2 + 1 + 1 + 1 (1-indexed)
resCol: 7, // 4 + 1 + 1 + 1 (1-indexed)
resOffset: 13, // 7 (length of first line) + 4 + 1 + 1
pre: "𐐀45",
post: "",
},
{
scenario: "cursor beyond end of file",
input: funnyString,
line: 2,
offset: 7,
utf16col: 6, // 2 + 1 + 1 + 1 + 1(1-indexed)
resCol: 8, // 4 + 1 + 1 + 1 + 1 (1-indexed)
resOffset: 14, // 7 (length of first line) + 4 + 1 + 1 + 1
err: "FromUTF16Column: chr goes beyond the content",
},
{
scenario: "offset beyond end of file",
input: funnyString,
line: 2,
offset: 14,
utf16col: 2,
err: "FromUTF16Column: offset (14) greater than length of content (13)",
},
}
func TestToUTF16(t *testing.T) {
for _, e := range toUTF16Tests {
t.Run(e.scenario, func(t *testing.T) {
if e.issue != nil && !*e.issue {
t.Skip("expected to fail")
}
p := span.NewPoint(e.line, e.col, e.offset)
got, err := span.ToUTF16Column(p, e.input)
if err != nil {
if err.Error() != e.err {
t.Fatalf("expected error %v; got %v", e.err, err)
}
return
}
if e.err != "" {
t.Fatalf("unexpected success; wanted %v", e.err)
}
if got != e.resUTF16col {
t.Fatalf("expected result %v; got %v", e.resUTF16col, got)
}
pre, post := getPrePost(e.input, p.Offset())
if string(pre) != e.pre {
t.Fatalf("expected #%d pre %q; got %q", p.Offset(), e.pre, pre)
}
if string(post) != e.post {
t.Fatalf("expected #%d, post %q; got %q", p.Offset(), e.post, post)
}
})
}
}
func TestFromUTF16(t *testing.T) {
for _, e := range fromUTF16Tests {
t.Run(e.scenario, func(t *testing.T) {
p := span.NewPoint(e.line, 1, e.offset)
p, err := span.FromUTF16Column(p, e.utf16col, []byte(e.input))
if err != nil {
if err.Error() != e.err {
t.Fatalf("expected error %v; got %v", e.err, err)
}
return
}
if e.err != "" {
t.Fatalf("unexpected success; wanted %v", e.err)
}
if p.Column() != e.resCol {
t.Fatalf("expected resulting col %v; got %v", e.resCol, p.Column())
}
if p.Offset() != e.resOffset {
t.Fatalf("expected resulting offset %v; got %v", e.resOffset, p.Offset())
}
pre, post := getPrePost(e.input, p.Offset())
if string(pre) != e.pre {
t.Fatalf("expected #%d pre %q; got %q", p.Offset(), e.pre, pre)
}
if string(post) != e.post {
t.Fatalf("expected #%d post %q; got %q", p.Offset(), e.post, post)
}
})
}
}
func getPrePost(content []byte, offset int) (string, string) {
pre, post := string(content)[:offset], string(content)[offset:]
if i := strings.LastIndex(pre, "\n"); i >= 0 {
pre = pre[i+1:]
}
if i := strings.IndexRune(post, '\n'); i >= 0 {
post = post[:i]
}
return pre, post
}