Add checker for different usage of type in func arguments

checkers.go

@@ -676,3 +676,39 @@ func (c *unitImportChecker) Visit(n ast.Node) bool {
 	}
 	return false
 }
+
+type sameTypeArgumentsChecker struct {
+	checkerBase
+
+	allTypesPresent     opVariant
+	optionalTypesOmited opVariant
+}
+
+func newSameTypeArgumentsChecker(ctxt *context) checker {
+	c := &sameTypeArgumentsChecker{}
+	c.ctxt = ctxt
+	c.allTypesPresent.warning = "use types always after each argument"
+	c.optionalTypesOmited.warning = "use only one type declaration after several arguments of the same type"
+	c.op = &operation{
+		name:     "same type arguments",
+		variants: []*opVariant{&c.allTypesPresent, &c.optionalTypesOmited},
+	}
+	return c
+}
+
+func (c *sameTypeArgumentsChecker) Visit(n ast.Node) bool {
+	fun, ok := n.(*ast.FuncDecl)
+	if !ok {
+		return true
+	}
+
+	for _, param := range fun.Type.Params.List {
+		if len(param.Names) > 1 {
+			c.ctxt.mark(n, &c.optionalTypesOmited)
+		} else {
+			c.ctxt.mark(n, &c.allTypesPresent)
+		}
+	}
+
+	return false
+}

end2end_test.go

@@ -16,6 +16,7 @@ func TestEnd2End(t *testing.T) {
 		"negative_tests1.go",
 		"negative_tests2.go",
 		"negative_tests3.go",
+		"negative_tests4.go",
 	}
 
 	for _, filename := range filenames {

go.mod

@@ -1,8 +1,11 @@
 module github.com/Quasilyte/go-consistent
 
 require (
-	github.com/go-toolsmith/astequal v0.0.0-20180903214952-dcb477bfacd6
+	github.com/go-toolsmith/astcast v1.0.0
+	github.com/go-toolsmith/astequal v1.0.0
 	github.com/go-toolsmith/astinfo v0.0.0-20180906194353-9809ff7efb21
+	github.com/go-toolsmith/pkgload v1.0.0
+	github.com/go-toolsmith/typep v1.0.0
 	github.com/kisielk/gotool v1.0.0
-	golang.org/x/tools v0.0.0-20181024171208-a2dc47679d30
+	golang.org/x/tools v0.0.0-20190110163146-51295c7ec13a
 )

go.sum

@@ -1,8 +1,19 @@
+github.com/go-toolsmith/astcast v1.0.0 h1:JojxlmI6STnFVG9yOImLeGREv8W2ocNUM+iOhR6jE7g=
+github.com/go-toolsmith/astcast v1.0.0/go.mod h1:mt2OdQTeAQcY4DQgPSArJjHCcOwlX+Wl/kwN+LbLGQ4=
 github.com/go-toolsmith/astequal v0.0.0-20180903214952-dcb477bfacd6 h1:aTBUNRTatDDU24gbOEKEoLiDwxtc98ga6K/iMTm6fvs=
 github.com/go-toolsmith/astequal v0.0.0-20180903214952-dcb477bfacd6/go.mod h1:H+xSiq0+LtiDC11+h1G32h7Of5O3CYFJ99GVbS5lDKY=
+github.com/go-toolsmith/astequal v1.0.0 h1:4zxD8j3JRFNyLN46lodQuqz3xdKSrur7U/sr0SDS/gQ=
+github.com/go-toolsmith/astequal v1.0.0/go.mod h1:H+xSiq0+LtiDC11+h1G32h7Of5O3CYFJ99GVbS5lDKY=
 github.com/go-toolsmith/astinfo v0.0.0-20180906194353-9809ff7efb21 h1:wP6mXeB2V/d1P1K7bZ5vDUO3YqEzcvOREOxZPEu3gVI=
 github.com/go-toolsmith/astinfo v0.0.0-20180906194353-9809ff7efb21/go.mod h1:dDStQCHtmZpYOmjRP/8gHHnCCch3Zz3oEgCdZVdtweU=
+github.com/go-toolsmith/pkgload v1.0.0 h1:4DFWWMXVfbcN5So1sBNW9+yeiMqLFGl1wFLTL5R0Tgg=
+github.com/go-toolsmith/pkgload v1.0.0/go.mod h1:5eFArkbO80v7Z0kdngIxsRXRMTaX4Ilcwuh3clNrQJc=
+github.com/go-toolsmith/strparse v1.0.0/go.mod h1:YI2nUKP9YGZnL/L1/DLFBfixrcjslWct4wyljWhSRy8=
+github.com/go-toolsmith/typep v1.0.0 h1:zKymWyA1TRYvqYrYDrfEMZULyrhcnGY3x7LDKU2XQaA=
+github.com/go-toolsmith/typep v1.0.0/go.mod h1:JSQCQMUPdRlMZFswiq3TGpNp1GMktqkR2Ns5AIQkATU=
 github.com/kisielk/gotool v1.0.0 h1:AV2c/EiW3KqPNT9ZKl07ehoAGi4C5/01Cfbblndcapg=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
 golang.org/x/tools v0.0.0-20181024171208-a2dc47679d30 h1:iZIABIEHjQFp5zqGZgQiaXi5Ue5czJhXyylr2CTtdRY=
 golang.org/x/tools v0.0.0-20181024171208-a2dc47679d30/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190110163146-51295c7ec13a h1:sSIx6lCxXoSnDgf7mm3vA/EYXI/gFaJupV18uYCUDmQ=
+golang.org/x/tools v0.0.0-20190110163146-51295c7ec13a/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

testdata/negative_tests4.go

@@ -0,0 +1,13 @@
+package ntests4
+
+// In this test suite function definitions have all types. No warnings should be generated.
+
+func someFunc(
+	a int, b int, c int, d string, e string,
+) {
+	return
+}
+
+func someOtherFunc(a int, b int, c int) {
+	return
+}

testdata/positive_tests1.go

@@ -157,3 +157,15 @@ func defaultCaseOrder(x int, v interface{}) {
 	default:
 	}
 }
+
+func allTypes(a int, b int, c int) {
+	return
+}
+
+func allTypes2(a int, b int, c int) {
+	return
+}
+
+func omitTypes(a, b, c int) { //= use types always after each argument
+	return
+}

testdata/positive_tests2.go

@@ -160,3 +160,15 @@ func defaultCaseOrder(x int, v interface{}) {
 	default:
 	}
 }
+
+func omitTypes(a, b, c int) {
+	return
+}
+
+func omitTypes2(a, b, c int) {
+	return
+}
+
+func allTypes(a int, b int, c int) { //= use only one type declaration after several arguments of the same type
+	return
+}