cmd/stringer: add -trimprefix option
To trim a string prefix from the names when generating their final
strings. Add a simple test too.
There is no automatic detection of prefixes for now. That can be added
later, building on top of this first simple implementation.
Fixes #16539.
Change-Id: Ica37273ac74bb0a6cbd43e61823786963d86a492
Reviewed-on: https://go-review.googlesource.com/76650
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/cmd/stringer/golden_test.go b/cmd/stringer/golden_test.go
index 12df238..166fc03 100644
--- a/cmd/stringer/golden_test.go
+++ b/cmd/stringer/golden_test.go
@@ -16,18 +16,20 @@
// Golden represents a test case.
type Golden struct {
- name string
- input string // input; the package clause is provided when running the test.
- output string // exected output.
+ name string
+ trimPrefix string
+ input string // input; the package clause is provided when running the test.
+ output string // exected output.
}
var golden = []Golden{
- {"day", day_in, day_out},
- {"offset", offset_in, offset_out},
- {"gap", gap_in, gap_out},
- {"num", num_in, num_out},
- {"unum", unum_in, unum_out},
- {"prime", prime_in, prime_out},
+ {"day", "", day_in, day_out},
+ {"offset", "", offset_in, offset_out},
+ {"gap", "", gap_in, gap_out},
+ {"num", "", num_in, num_out},
+ {"unum", "", unum_in, unum_out},
+ {"prime", "", prime_in, prime_out},
+ {"prefix", "Type", prefix_in, prefix_out},
}
// Each example starts with "type XXX [u]int", with a single space separating them.
@@ -238,9 +240,34 @@
}
`
+const prefix_in = `type Type int
+const (
+ TypeInt Type = iota
+ TypeString
+ TypeFloat
+ TypeRune
+ TypeByte
+ TypeStruct
+ TypeSlice
+)
+`
+
+const prefix_out = `
+const _Type_name = "IntStringFloatRuneByteStructSlice"
+
+var _Type_index = [...]uint8{0, 3, 9, 14, 18, 22, 28, 33}
+
+func (i Type) String() string {
+ if i < 0 || i >= Type(len(_Type_index)-1) {
+ return fmt.Sprintf("Type(%d)", i)
+ }
+ return _Type_name[_Type_index[i]:_Type_index[i+1]]
+}
+`
+
func TestGolden(t *testing.T) {
for _, test := range golden {
- var g Generator
+ g := Generator{trimPrefix: test.trimPrefix}
input := "package test\n" + test.input
file := test.name + ".go"
g.parsePackage(".", []string{file}, input)
diff --git a/cmd/stringer/stringer.go b/cmd/stringer/stringer.go
index f741d98..2ae36e8 100644
--- a/cmd/stringer/stringer.go
+++ b/cmd/stringer/stringer.go
@@ -78,8 +78,9 @@
)
var (
- typeNames = flag.String("type", "", "comma-separated list of type names; must be set")
- output = flag.String("output", "", "output file name; default srcdir/<type>_string.go")
+ typeNames = flag.String("type", "", "comma-separated list of type names; must be set")
+ output = flag.String("output", "", "output file name; default srcdir/<type>_string.go")
+ trimprefix = flag.String("trimprefix", "", "trim the `prefix` from the generated constant names")
)
// Usage is a replacement usage function for the flags package.
@@ -112,10 +113,8 @@
}
// Parse the package once.
- var (
- dir string
- g Generator
- )
+ var dir string
+ g := Generator{trimPrefix: *trimprefix}
if len(args) == 1 && isDirectory(args[0]) {
dir = args[0]
g.parsePackageDir(args[0])
@@ -165,6 +164,8 @@
type Generator struct {
buf bytes.Buffer // Accumulated output.
pkg *Package // Package we are scanning.
+
+ trimPrefix string
}
func (g *Generator) Printf(format string, args ...interface{}) {
@@ -178,6 +179,8 @@
// These fields are reset for each type being generated.
typeName string // Name of the constant type.
values []Value // Accumulator for constant values of that type.
+
+ trimPrefix string
}
type Package struct {
@@ -240,8 +243,9 @@
}
astFiles = append(astFiles, parsedFile)
files = append(files, &File{
- file: parsedFile,
- pkg: g.pkg,
+ file: parsedFile,
+ pkg: g.pkg,
+ trimPrefix: g.trimPrefix,
})
}
if len(astFiles) == 0 {
@@ -453,6 +457,7 @@
signed: info&types.IsUnsigned == 0,
str: value.String(),
}
+ v.name = strings.TrimPrefix(v.name, f.trimPrefix)
f.values = append(f.values, v)
}
}
