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|
package collapse
import (
"regexp"
"strings"
"testing"
)
// This is the alternative (but slower) function that uses regex.
func _regexReplaceAnyWhitespaceWithSpace(text string) string {
var rAnyWhitespace = regexp.MustCompile(`[ \r\n\t]+`)
return rAnyWhitespace.ReplaceAllString(text, " ")
}
func TestReplaceAnyWhitespaceWithSpace(t *testing.T) {
runs := []struct {
desc string
input string
expected string
}{
{
desc: "empty",
input: "",
expected: "",
},
{
desc: "one space",
input: " ",
expected: " ",
},
{
desc: "two spaces",
input: " ",
expected: " ",
},
{
desc: "many spaces",
input: " ",
expected: " ",
},
{
desc: "one newline",
input: "\n",
expected: " ",
},
{
desc: "many newlines",
input: "\n\n\n\n",
expected: " ",
},
{
desc: "combination of newlines and spaces",
input: "\n a \nb \nc\n",
expected: " a b c ",
},
{
desc: "special dash",
input: " \u2013 ",
expected: " \u2013 ",
},
{
desc: "no spaces in text",
input: "abcdef",
expected: "abcdef",
},
{
desc: "one space in text",
input: "abc def",
expected: "abc def",
},
{
desc: "two spaces in text",
input: "abc def",
expected: "abc def",
},
{
desc: "one newline in text",
input: "abc\ndef",
expected: "abc def",
},
{
desc: "two newlines in text",
input: "abc\n\ndef",
expected: "abc def",
},
{
desc: "a newline and space in text",
input: "abc \ndef",
expected: "abc def",
},
{
desc: "one space before text",
input: " abcdef",
expected: " abcdef",
},
{
desc: "two spaces before text",
input: " abcdef",
expected: " abcdef",
},
{
desc: "one space after text",
input: "abcdef ",
expected: "abcdef ",
},
{
desc: "two spaces after text",
input: "abcdef ",
expected: "abcdef ",
},
{
desc: "multiple spaces before & one space after",
input: " or ",
expected: " or ",
},
{
desc: "multiple spaces before & multiple spaces after",
input: " or ",
expected: " or ",
},
{
desc: "one space before & multiple spaces after",
input: " or ",
expected: " or ",
},
}
for _, run := range runs {
t.Run(run.desc, func(t *testing.T) {
t.Run("Regex Version", func(t *testing.T) {
output := _regexReplaceAnyWhitespaceWithSpace(run.input)
if output != run.expected {
t.Errorf("expected %q but got %q", run.expected, output)
}
})
t.Run("New Version", func(t *testing.T) {
output := replaceAnyWhitespaceWithSpace(run.input)
if output != run.expected {
t.Errorf("expected %q but got %q", run.expected, output)
}
// Instead of writing all tests twice...
output2 := replaceAnyWhitespaceWithSpace(strings.ReplaceAll(run.input, " ", "\n"))
if output2 != run.expected {
t.Errorf("for newlines: expected %q but got %q", run.expected, output2)
}
})
})
}
}
func FuzzReplaceAnyWhitespaceWithSpace(f *testing.F) {
f.Add("abc def")
f.Add(" ")
f.Add("abc\n\ndef")
f.Fuzz(func(t *testing.T, orig string) {
output1 := _regexReplaceAnyWhitespaceWithSpace(orig)
output2 := replaceAnyWhitespaceWithSpace(orig)
if output1 != output2 {
t.Errorf("input:%q => regex: %q function: %q", orig, output1, output2)
}
})
}
func TestReplaceAnyWhitespaceWithSpace_Allocs(t *testing.T) {
const N = 1000
runs := []struct {
desc string
input string
expectedAllocs float64
}{
{
desc: "empty string",
input: "",
expectedAllocs: 0,
},
{
desc: "one space",
input: " ",
expectedAllocs: 0,
},
{
desc: "no spaces",
input: "abcdef",
expectedAllocs: 0,
},
{
desc: "one space at start",
input: " abcdef",
expectedAllocs: 0,
},
{
desc: "one space at end",
input: "abcdef ",
expectedAllocs: 0,
},
{
desc: "one space in middle",
input: "abc def",
expectedAllocs: 0,
},
{
desc: "one space at start, middle and end",
input: " abc def ",
expectedAllocs: 0,
},
{
desc: "one space at start, middle and end",
input: "some longer text with spaces",
expectedAllocs: 0,
},
{
desc: "multiple spaces",
input: "abc def",
expectedAllocs: 1,
},
{
desc: "multiple newlines & spaces",
input: "\n\nab cdef \n",
expectedAllocs: 1,
},
{
desc: "longer string",
input: strings.Repeat("Lorem Ipsum is simply dummy text", 10),
expectedAllocs: 0,
},
}
for _, run := range runs {
t.Run(run.desc, func(t *testing.T) {
avg := testing.AllocsPerRun(N, func() {
output := replaceAnyWhitespaceWithSpace(run.input)
_ = output
})
if avg != run.expectedAllocs {
t.Errorf("expected %f allocations but got %f", run.expectedAllocs, avg)
}
})
}
}
|
