pkg/analyzers: add 'var' analyzer

README.md

@@ -34,4 +34,9 @@ GOPATH/src/github.com/leonklingele/grouper/pkg/analyzer/flags.go:3:1: should onl
     	require the use of grouped global 'type' declarations
   -type-require-single-type
     	require the use of a single global 'type' declaration only
+
+  -var-require-grouping
+    	require the use of grouped global 'var' declarations
+  -var-require-single-var
+    	require the use of a single global 'var' declaration only
 ```

pkg/analyzer/analyzer.go

@@ -7,14 +7,15 @@ import (
 	"github.com/leonklingele/grouper/pkg/analyzer/consts"
 	"github.com/leonklingele/grouper/pkg/analyzer/imports"
 	"github.com/leonklingele/grouper/pkg/analyzer/types"
+	"github.com/leonklingele/grouper/pkg/analyzer/vars"
 
 	"golang.org/x/tools/go/analysis"
 	"golang.org/x/tools/go/analysis/passes/inspect"
 )
 
 const (
 	Name = "grouper"
-	Doc  = `expression group analyzer: require 'import', 'const' and/or 'var' declaration groups`
+	Doc  = `expression group analyzer: require 'import', 'const', 'var' and/or 'type' declaration groups`
 )
 
 func New() *analysis.Analyzer {
@@ -47,6 +48,11 @@ func run(p *analysis.Pass) (interface{}, error) {
 			RequireSingleType: flagLookupBool(FlagNameTypeRequireSingleType),
 			RequireGrouping:   flagLookupBool(FlagNameTypeRequireGrouping),
 		},
+
+		VarsConfig: &vars.Config{
+			RequireSingleVar: flagLookupBool(FlagNameVarRequireSingleVar),
+			RequireGrouping:  flagLookupBool(FlagNameVarRequireGrouping),
+		},
 	}
 
 	return nil, pass(c, p)
@@ -75,5 +81,9 @@ func filepass(c *Config, p *analysis.Pass, f *ast.File) error {
 		return fmt.Errorf("failed to types.Filepass: %w", err)
 	}
 
+	if err := vars.Filepass(c.VarsConfig, p, f); err != nil {
+		return fmt.Errorf("failed to vars.Filepass: %w", err)
+	}
+
 	return nil
 }

pkg/analyzer/analyzer_test.go

@@ -225,6 +225,85 @@ func TestType(t *testing.T) {
 	}
 }
 
+func TestVar(t *testing.T) {
+	t.Parallel()
+
+	fixtures := []struct {
+		name  string
+		flags flag.FlagSet
+	}{
+		{
+			name: "single-grouped",
+			flags: flags().
+				withVarRequireGrouping().
+				build(),
+		},
+		{
+			name: "single-ungrouped",
+			flags: flags().
+				withVarRequireGrouping().
+				build(),
+		},
+
+		{
+			name: "multi-grouped",
+			flags: flags().
+				withVarRequireSingleVar().
+				withVarRequireGrouping().
+				build(),
+		},
+		{
+			name: "multi-ungrouped",
+			flags: flags().
+				withVarRequireSingleVar().
+				withVarRequireGrouping().
+				build(),
+		},
+
+		{
+			name: "mixed-require-single-var",
+			flags: flags().
+				withVarRequireSingleVar().
+				build(),
+		},
+		{
+			name: "mixed-require-grouping",
+			flags: flags().
+				withVarRequireGrouping().
+				build(),
+		},
+
+		{
+			name: "mixed-named-with-consts",
+			flags: flags().
+				withVarRequireSingleVar().
+				withVarRequireGrouping().
+				build(),
+		},
+		{
+			name: "mixed-named-with-var-shorthand",
+			flags: flags().
+				withVarRequireSingleVar().
+				withVarRequireGrouping().
+				build(),
+		},
+	}
+
+	for _, f := range fixtures {
+		f := f
+
+		t.Run(f.name, func(t *testing.T) {
+			t.Parallel()
+
+			a := analyzer.New()
+			a.Flags = f.flags
+
+			testdata := filepath.Join(analysistest.TestData(), "var")
+			_ = analysistest.Run(t, testdata, a, f.name)
+		})
+	}
+}
+
 type flagger struct {
 	fs *flag.FlagSet
 }
@@ -277,6 +356,22 @@ func (f *flagger) withTypeRequireGrouping() *flagger {
 	return f
 }
 
+func (f *flagger) withVarRequireSingleVar() *flagger {
+	if err := f.fs.Lookup(analyzer.FlagNameVarRequireSingleVar).Value.Set("true"); err != nil {
+		panic(err)
+	}
+
+	return f
+}
+
+func (f *flagger) withVarRequireGrouping() *flagger {
+	if err := f.fs.Lookup(analyzer.FlagNameVarRequireGrouping).Value.Set("true"); err != nil {
+		panic(err)
+	}
+
+	return f
+}
+
 func (f *flagger) build() flag.FlagSet {
 	return *f.fs
 }

pkg/analyzer/config.go

@@ -4,10 +4,12 @@ import (
 	"github.com/leonklingele/grouper/pkg/analyzer/consts"
 	"github.com/leonklingele/grouper/pkg/analyzer/imports"
 	"github.com/leonklingele/grouper/pkg/analyzer/types"
+	"github.com/leonklingele/grouper/pkg/analyzer/vars"
 )
 
 type Config struct {
 	ConstsConfig  *consts.Config
 	ImportsConfig *imports.Config
 	TypesConfig   *types.Config
+	VarsConfig    *vars.Config
 }

pkg/analyzer/flags.go

@@ -13,6 +13,9 @@ const (
 
 	FlagNameTypeRequireSingleType = "type-require-single-type"
 	FlagNameTypeRequireGrouping   = "type-require-grouping"
+
+	FlagNameVarRequireSingleVar = "var-require-single-var"
+	FlagNameVarRequireGrouping  = "var-require-grouping"
 )
 
 func Flags() flag.FlagSet {
@@ -27,5 +30,8 @@ func Flags() flag.FlagSet {
 	fs.Bool(FlagNameTypeRequireSingleType, false, "require the use of a single global 'type' declaration only")
 	fs.Bool(FlagNameTypeRequireGrouping, false, "require the use of grouped global 'type' declarations")
 
+	fs.Bool(FlagNameVarRequireSingleVar, false, "require the use of a single global 'var' declaration only")
+	fs.Bool(FlagNameVarRequireGrouping, false, "require the use of grouped global 'var' declarations")
+
 	return *fs
 }

pkg/analyzer/testdata/var/src/mixed-named-with-consts/testcase.go

@@ -0,0 +1,52 @@
+package testcase
+
+var (
+	a = "a"
+	b = "b"
+
+	_ = "underscore1"
+)
+
+var ( // want "should only use a single global 'var' declaration, 5 found"
+	comment1 = "comment1" // some comment
+)
+
+const ignoreconst1 = "ignoreconst1"
+const (
+	ignoreconst2 = "ignoreconst2"
+	ignoreconst3 = "ignoreconst3"
+)
+
+func dummy() {
+	var (
+		ignorea = "ignorea"
+		ignoreb = "ignoreb"
+
+		_ = "ignoreunderscore1"
+	)
+
+	var (
+		ignorecomment1 = "ignorecomment1" // some comment
+	)
+
+	var ignorec = "ignorec"
+	var _ = "ignoreunderscore2"
+
+	var ()
+
+	_ = a
+	_ = b
+	_ = c
+	_ = comment1
+	_ = comment2
+	_ = ignorecomment1
+	_ = ignorea
+	_ = ignoreb
+	_ = ignorec
+}
+
+var c = "c" // want "should only use grouped global 'var' declarations"
+
+var comment2 = "comment2" // some comment
+
+var ()

pkg/analyzer/testdata/var/src/mixed-named-with-var-shorthand/testcase.go

@@ -0,0 +1,55 @@
+package testcase
+
+var (
+	a = "a"
+	b = "b"
+
+	_ = "underscore1"
+)
+
+var ( // want "should only use a single global 'var' declaration, 5 found"
+	comment1 = "comment1" // some comment
+)
+
+const ignoreconst1 = "ignoreconst1"
+const (
+	ignoreconst2 = "ignoreconst2"
+	ignoreconst3 = "ignoreconst3"
+)
+
+func dummy() {
+	var (
+		ignorea = "ignorea"
+		ignoreb = "ignoreb"
+
+		_ = "ignoreunderscore1"
+	)
+
+	var (
+		ignorecomment1 = "ignorecomment1" // some comment
+	)
+
+	var ignorec = "ignorec"
+	var _ = "ignoreunderscore2"
+
+	var ()
+
+	_ = a
+	_ = b
+	_ = c
+	_ = comment1
+	_ = comment2
+	_ = ignorecomment1
+	_ = ignorea
+	_ = ignoreb
+	_ = ignorec
+
+	hello := "world"
+	println(hello)
+}
+
+var c = "c" // want "should only use grouped global 'var' declarations"
+
+var comment2 = "comment2" // some comment
+
+var ()

pkg/analyzer/testdata/var/src/mixed-require-grouping/testcase.go

@@ -0,0 +1,37 @@
+package testcase
+
+var (
+	a = "a"
+	b = "b"
+
+	_ = "underscore1"
+)
+
+var (
+	comment1 = "comment1" // some comment
+)
+
+var c = "c" // want "should only use grouped global 'var' declarations"
+
+var comment2 = "comment2" // some comment
+
+var ()
+
+func dummy() {
+	var (
+		_ = "ignore1"
+		_ = "ignore2"
+	)
+
+	var (
+		_ = "ignore3"
+	)
+
+	var d = "d"
+	var comment3 = "comment3" // some comment
+
+	println(d)
+	println(comment3)
+
+	var ()
+}

pkg/analyzer/testdata/var/src/mixed-require-single-var/testcase.go

@@ -0,0 +1,37 @@
+package testcase
+
+var (
+	a = "a"
+	b = "b"
+
+	_ = "underscore1"
+)
+
+var ( // want "should only use a single global 'var' declaration, 5 found"
+	comment1 = "comment1" // some comment
+)
+
+var c = "c"
+
+var comment2 = "comment2" // some comment
+
+var ()
+
+func dummy() {
+	var (
+		_ = "ignore1"
+		_ = "ignore2"
+	)
+
+	var (
+		_ = "ignore3"
+	)
+
+	var d = "d"
+	var comment3 = "comment3" // some comment
+
+	println(d)
+	println(comment3)
+
+	var ()
+}

pkg/analyzer/testdata/var/src/multi-grouped/testcase.go

@@ -0,0 +1,15 @@
+package testcase
+
+var (
+	a = "a"
+	b = "b"
+
+	_ = "underscore1"
+)
+
+func dummy() {
+	var (
+		_ = "ignore1"
+		_ = "ignore2"
+	)
+}