mirror of
https://github.com/VictoriaMetrics/VictoriaMetrics.git
synced 2024-11-21 14:44:00 +00:00
485 lines
9.9 KiB
Go
485 lines
9.9 KiB
Go
package simple
|
||
|
||
import "honnef.co/go/tools/lint"
|
||
|
||
var Docs = map[string]*lint.Documentation{
|
||
"S1000": {
|
||
Title: `Use plain channel send or receive instead of single-case select`,
|
||
Text: `Select statements with a single case can be replaced with a simple
|
||
send or receive.
|
||
|
||
Before:
|
||
|
||
select {
|
||
case x := <-ch:
|
||
fmt.Println(x)
|
||
}
|
||
|
||
After:
|
||
|
||
x := <-ch
|
||
fmt.Println(x)`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1001": {
|
||
Title: `Replace for loop with call to copy`,
|
||
Text: `Use copy() for copying elements from one slice to another.
|
||
|
||
Before:
|
||
|
||
for i, x := range src {
|
||
dst[i] = x
|
||
}
|
||
|
||
After:
|
||
|
||
copy(dst, src)`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1002": {
|
||
Title: `Omit comparison with boolean constant`,
|
||
Text: `Before:
|
||
|
||
if x == true {}
|
||
|
||
After:
|
||
|
||
if x {}`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1003": {
|
||
Title: `Replace call to strings.Index with strings.Contains`,
|
||
Text: `Before:
|
||
|
||
if strings.Index(x, y) != -1 {}
|
||
|
||
After:
|
||
|
||
if strings.Contains(x, y) {}`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1004": {
|
||
Title: `Replace call to bytes.Compare with bytes.Equal`,
|
||
Text: `Before:
|
||
|
||
if bytes.Compare(x, y) == 0 {}
|
||
|
||
After:
|
||
|
||
if bytes.Equal(x, y) {}`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1005": {
|
||
Title: `Drop unnecessary use of the blank identifier`,
|
||
Text: `In many cases, assigning to the blank identifier is unnecessary.
|
||
|
||
Before:
|
||
|
||
for _ = range s {}
|
||
x, _ = someMap[key]
|
||
_ = <-ch
|
||
|
||
After:
|
||
|
||
for range s{}
|
||
x = someMap[key]
|
||
<-ch`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1006": {
|
||
Title: `Use for { ... } for infinite loops`,
|
||
Text: `For infinite loops, using for { ... } is the most idiomatic choice.`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1007": {
|
||
Title: `Simplify regular expression by using raw string literal`,
|
||
Text: `Raw string literals use ` + "`" + ` instead of " and do not support
|
||
any escape sequences. This means that the backslash (\) can be used
|
||
freely, without the need of escaping.
|
||
|
||
Since regular expressions have their own escape sequences, raw strings
|
||
can improve their readability.
|
||
|
||
Before:
|
||
|
||
regexp.Compile("\\A(\\w+) profile: total \\d+\\n\\z")
|
||
|
||
After:
|
||
|
||
regexp.Compile(` + "`" + `\A(\w+) profile: total \d+\n\z` + "`" + `)`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1008": {
|
||
Title: `Simplify returning boolean expression`,
|
||
Text: `Before:
|
||
|
||
if <expr> {
|
||
return true
|
||
}
|
||
return false
|
||
|
||
After:
|
||
|
||
return <expr>`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1009": {
|
||
Title: `Omit redundant nil check on slices`,
|
||
Text: `The len function is defined for all slices, even nil ones, which have
|
||
a length of zero. It is not necessary to check if a slice is not nil
|
||
before checking that its length is not zero.
|
||
|
||
Before:
|
||
|
||
if x != nil && len(x) != 0 {}
|
||
|
||
After:
|
||
|
||
if len(x) != 0 {}`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1010": {
|
||
Title: `Omit default slice index`,
|
||
Text: `When slicing, the second index defaults to the length of the value,
|
||
making s[n:len(s)] and s[n:] equivalent.`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1011": {
|
||
Title: `Use a single append to concatenate two slices`,
|
||
Text: `Before:
|
||
|
||
for _, e := range y {
|
||
x = append(x, e)
|
||
}
|
||
|
||
After:
|
||
|
||
x = append(x, y...)`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1012": {
|
||
Title: `Replace time.Now().Sub(x) with time.Since(x)`,
|
||
Text: `The time.Since helper has the same effect as using time.Now().Sub(x)
|
||
but is easier to read.
|
||
|
||
Before:
|
||
|
||
time.Now().Sub(x)
|
||
|
||
After:
|
||
|
||
time.Since(x)`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1016": {
|
||
Title: `Use a type conversion instead of manually copying struct fields`,
|
||
Text: `Two struct types with identical fields can be converted between each
|
||
other. In older versions of Go, the fields had to have identical
|
||
struct tags. Since Go 1.8, however, struct tags are ignored during
|
||
conversions. It is thus not necessary to manually copy every field
|
||
individually.
|
||
|
||
Before:
|
||
|
||
var x T1
|
||
y := T2{
|
||
Field1: x.Field1,
|
||
Field2: x.Field2,
|
||
}
|
||
|
||
After:
|
||
|
||
var x T1
|
||
y := T2(x)`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1017": {
|
||
Title: `Replace manual trimming with strings.TrimPrefix`,
|
||
Text: `Instead of using strings.HasPrefix and manual slicing, use the
|
||
strings.TrimPrefix function. If the string doesn't start with the
|
||
prefix, the original string will be returned. Using strings.TrimPrefix
|
||
reduces complexity, and avoids common bugs, such as off-by-one
|
||
mistakes.
|
||
|
||
Before:
|
||
|
||
if strings.HasPrefix(str, prefix) {
|
||
str = str[len(prefix):]
|
||
}
|
||
|
||
After:
|
||
|
||
str = strings.TrimPrefix(str, prefix)`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1018": {
|
||
Title: `Use copy for sliding elements`,
|
||
Text: `copy() permits using the same source and destination slice, even with
|
||
overlapping ranges. This makes it ideal for sliding elements in a
|
||
slice.
|
||
|
||
Before:
|
||
|
||
for i := 0; i < n; i++ {
|
||
bs[i] = bs[offset+i]
|
||
}
|
||
|
||
After:
|
||
|
||
copy(bs[:n], bs[offset:])`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1019": {
|
||
Title: `Simplify make call by omitting redundant arguments`,
|
||
Text: `The make function has default values for the length and capacity
|
||
arguments. For channels and maps, the length defaults to zero.
|
||
Additionally, for slices the capacity defaults to the length.`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1020": {
|
||
Title: `Omit redundant nil check in type assertion`,
|
||
Text: `Before:
|
||
|
||
if _, ok := i.(T); ok && i != nil {}
|
||
|
||
After:
|
||
|
||
if _, ok := i.(T); ok {}`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1021": {
|
||
Title: `Merge variable declaration and assignment`,
|
||
Text: `Before:
|
||
|
||
var x uint
|
||
x = 1
|
||
|
||
After:
|
||
|
||
var x uint = 1`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1023": {
|
||
Title: `Omit redundant control flow`,
|
||
Text: `Functions that have no return value do not need a return statement as
|
||
the final statement of the function.
|
||
|
||
Switches in Go do not have automatic fallthrough, unlike languages
|
||
like C. It is not necessary to have a break statement as the final
|
||
statement in a case block.`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1024": {
|
||
Title: `Replace x.Sub(time.Now()) with time.Until(x)`,
|
||
Text: `The time.Until helper has the same effect as using x.Sub(time.Now())
|
||
but is easier to read.
|
||
|
||
Before:
|
||
|
||
x.Sub(time.Now())
|
||
|
||
After:
|
||
|
||
time.Until(x)`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1025": {
|
||
Title: `Don't use fmt.Sprintf("%s", x) unnecessarily`,
|
||
Text: `In many instances, there are easier and more efficient ways of getting
|
||
a value's string representation. Whenever a value's underlying type is
|
||
a string already, or the type has a String method, they should be used
|
||
directly.
|
||
|
||
Given the following shared definitions
|
||
|
||
type T1 string
|
||
type T2 int
|
||
|
||
func (T2) String() string { return "Hello, world" }
|
||
|
||
var x string
|
||
var y T1
|
||
var z T2
|
||
|
||
we can simplify the following
|
||
|
||
fmt.Sprintf("%s", x)
|
||
fmt.Sprintf("%s", y)
|
||
fmt.Sprintf("%s", z)
|
||
|
||
to
|
||
|
||
x
|
||
string(y)
|
||
z.String()`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1028": {
|
||
Title: `Simplify error construction with fmt.Errorf`,
|
||
Text: `Before:
|
||
|
||
errors.New(fmt.Sprintf(...))
|
||
|
||
After:
|
||
|
||
fmt.Errorf(...)`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1029": {
|
||
Title: `Range over the string directly`,
|
||
Text: `Ranging over a string will yield byte offsets and runes. If the offset
|
||
isn't used, this is functionally equivalent to converting the string
|
||
to a slice of runes and ranging over that. Ranging directly over the
|
||
string will be more performant, however, as it avoids allocating a new
|
||
slice, the size of which depends on the length of the string.
|
||
|
||
Before:
|
||
|
||
for _, r := range []rune(s) {}
|
||
|
||
After:
|
||
|
||
for _, r := range s {}`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1030": {
|
||
Title: `Use bytes.Buffer.String or bytes.Buffer.Bytes`,
|
||
Text: `bytes.Buffer has both a String and a Bytes method. It is never
|
||
necessary to use string(buf.Bytes()) or []byte(buf.String()) – simply
|
||
use the other method.`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1031": {
|
||
Title: `Omit redundant nil check around loop`,
|
||
Text: `You can use range on nil slices and maps, the loop will simply never
|
||
execute. This makes an additional nil check around the loop
|
||
unnecessary.
|
||
|
||
Before:
|
||
|
||
if s != nil {
|
||
for _, x := range s {
|
||
...
|
||
}
|
||
}
|
||
|
||
After:
|
||
|
||
for _, x := range s {
|
||
...
|
||
}`,
|
||
Since: "2017.1",
|
||
},
|
||
|
||
"S1032": {
|
||
Title: `Use sort.Ints(x), sort.Float64s(x), and sort.Strings(x)`,
|
||
Text: `The sort.Ints, sort.Float64s and sort.Strings functions are easier to
|
||
read than sort.Sort(sort.IntSlice(x)), sort.Sort(sort.Float64Slice(x))
|
||
and sort.Sort(sort.StringSlice(x)).
|
||
|
||
Before:
|
||
|
||
sort.Sort(sort.StringSlice(x))
|
||
|
||
After:
|
||
|
||
sort.Strings(x)`,
|
||
Since: "2019.1",
|
||
},
|
||
|
||
"S1033": {
|
||
Title: `Unnecessary guard around call to delete`,
|
||
Text: `Calling delete on a nil map is a no-op.`,
|
||
Since: "2019.2",
|
||
},
|
||
|
||
"S1034": {
|
||
Title: `Use result of type assertion to simplify cases`,
|
||
Since: "2019.2",
|
||
},
|
||
|
||
"S1035": {
|
||
Title: `Redundant call to net/http.CanonicalHeaderKey in method call on net/http.Header`,
|
||
Text: `The methods on net/http.Header, namely Add, Del, Get and Set, already
|
||
canonicalize the given header name.`,
|
||
Since: "2020.1",
|
||
},
|
||
|
||
"S1036": {
|
||
Title: `Unnecessary guard around map access`,
|
||
|
||
Text: `When accessing a map key that doesn't exist yet, one
|
||
receives a zero value. Often, the zero value is a suitable value, for example when using append or doing integer math.
|
||
|
||
The following
|
||
|
||
if _, ok := m["foo"]; ok {
|
||
m["foo"] = append(m["foo"], "bar")
|
||
} else {
|
||
m["foo"] = []string{"bar"}
|
||
}
|
||
|
||
can be simplified to
|
||
|
||
m["foo"] = append(m["foo"], "bar")
|
||
|
||
and
|
||
|
||
if _, ok := m2["k"]; ok {
|
||
m2["k"] += 4
|
||
} else {
|
||
m2["k"] = 4
|
||
}
|
||
|
||
can be simplified to
|
||
|
||
m["k"] += 4
|
||
`,
|
||
Since: "2020.1",
|
||
},
|
||
|
||
"S1037": {
|
||
Title: `Elaborate way of sleeping`,
|
||
Text: `Using a select statement with a single case receiving
|
||
from the result of time.After is a very elaborate way of sleeping that
|
||
can much simpler be expressed with a simple call to time.Sleep.`,
|
||
Since: "2020.1",
|
||
},
|
||
|
||
"S1038": {
|
||
Title: "Unnecessarily complex way of printing formatted string",
|
||
Text: `Instead of using fmt.Print(fmt.Sprintf(...)), one can use fmt.Printf(...).`,
|
||
Since: "2020.1",
|
||
},
|
||
|
||
"S1039": {
|
||
Title: "Unnecessary use of fmt.Sprint",
|
||
Text: `Calling fmt.Sprint with a single string argument is unnecessary and identical to using the string directly.`,
|
||
Since: "2020.1",
|
||
},
|
||
}
|