cmd/doc: properly display interface methods

Previously, we used to call doc.ToText to print each comment
in a comment group attached to an interface method. This broke any
preformatted code block attached to the comment, and displayed everything
aligned to a single column. Additionally, the name of the interface
also wasn't displayed which didn't show which interface
the method belonged to.

To fix this, we print the entire interface node using format.Node
which takes care of displaying the comments correctly, and we also
filter out the methods that don't match, so that the method can be
displayed as belonging to an interface.

As an example, previously it would show:

// Comment before exported method.
//
// // Code block showing how to use ExportedMethod
// func DoSomething() error {
// ExportedMethod()
// return nil
// }
func ExportedMethod()  // Comment on line with exported method.

Now, it shows:

type ExportedInterface interface {
	// Comment before exported method.
	//
	//	// Code block showing how to use ExportedMethod
	//	func DoSomething() error {
	//		ExportedMethod()
	//		return nil
	//	}
	ExportedMethod() // Comment on line with exported method.

}

Fixes #43188

Change-Id: I28099fe4aab35e08049b2616a3506240f57133cc
Reviewed-on: https://go-review.googlesource.com/c/go/+/279433
Trust: Agniva De Sarker <agniva.quicksilver@gmail.com>
Trust: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Rob Pike <r@golang.org>

diff --git a/src/cmd/doc/doc_test.go b/src/cmd/doc/doc_test.go
index 39530e3c2d67dec54e8a274fc25e89ddcb8ad2a8..af7793133ef68bd0d064ee75a1f4e6f80e9396c5 100644 (file)
--- a/src/cmd/doc/doc_test.go
+++ b/src/cmd/doc/doc_test.go
@@ -579,7 +579,7 @@ var tests = []test{
                []string{
                        `Comment about exported interface`, // Include comment.
                        `type ExportedInterface interface`, // Interface definition.
-                       `Comment before exported method.*\n.*ExportedMethod\(\)` +
+                       `Comment before exported method.\n.*//\n.*//    // Code block showing how to use ExportedMethod\n.*//   func DoSomething\(\) error {\n.*//              ExportedMethod\(\)\n.*//                return nil\n.*//        }\n.*//.*\n.*ExportedMethod\(\)` +
                                `.*Comment on line with exported method`,
                        `io.Reader.*Comment on line with embedded Reader`,
                        `error.*Comment on line with embedded error`,
@@ -599,8 +599,7 @@ var tests = []test{
                []string{
                        `Comment about exported interface`, // Include comment.
                        `type ExportedInterface interface`, // Interface definition.
-                       `Comment before exported method.*\n.*ExportedMethod\(\)` +
-                               `.*Comment on line with exported method`,
+                       `Comment before exported method.\n.*//\n.*//    // Code block showing how to use ExportedMethod\n.*//   func DoSomething\(\) error {\n.*//              ExportedMethod\(\)\n.*//                return nil\n.*//        }\n.*//.*\n.*ExportedMethod\(\)` + `.*Comment on line with exported method`,
                        `unexportedMethod\(\).*Comment on line with unexported method`,
                        `io.Reader.*Comment on line with embedded Reader`,
                        `error.*Comment on line with embedded error`,
@@ -615,7 +614,7 @@ var tests = []test{
                "interface method",
                []string{p, `ExportedInterface.ExportedMethod`},
                []string{
-                       `Comment before exported method.*\n.*ExportedMethod\(\)` +
+                       `Comment before exported method.\n.*//\n.*//    // Code block showing how to use ExportedMethod\n.*//   func DoSomething\(\) error {\n.*//              ExportedMethod\(\)\n.*//                return nil\n.*//        }\n.*//.*\n.*ExportedMethod\(\)` +
                                `.*Comment on line with exported method`,
                },
                []string{

diff --git a/src/cmd/doc/pkg.go b/src/cmd/doc/pkg.go
index c2e06ebc8b071108d052d6e1b7cad049b038a8e8..587f0bdc1468f2fd23a2f15d8a097a89137f4fef 100644 (file)
--- a/src/cmd/doc/pkg.go
+++ b/src/cmd/doc/pkg.go
@@ -950,6 +950,9 @@ func (pkg *Package) printMethodDoc(symbol, method string) bool {
                        // Not an interface type.
                        continue
                }
+
+               // Collect and print only the methods that match.
+               var methods []*ast.Field
                for _, iMethod := range inter.Methods.List {
                        // This is an interface, so there can be only one name.
                        // TODO: Anonymous methods (embedding)
@@ -958,22 +961,21 @@ func (pkg *Package) printMethodDoc(symbol, method string) bool {
                        }
                        name := iMethod.Names[0].Name
                        if match(method, name) {
-                               if iMethod.Doc != nil {
-                                       for _, comment := range iMethod.Doc.List {
-                                               doc.ToText(&pkg.buf, comment.Text, "", indent, indentedWidth)
-                                       }
-                               }
-                               s := pkg.oneLineNode(iMethod.Type)
-                               // Hack: s starts "func" but there is no name present.
-                               // We could instead build a FuncDecl but it's not worthwhile.
-                               lineComment := ""
-                               if iMethod.Comment != nil {
-                                       lineComment = fmt.Sprintf("  %s", iMethod.Comment.List[0].Text)
-                               }
-                               pkg.Printf("func %s%s%s\n", name, s[4:], lineComment)
+                               methods = append(methods, iMethod)
                                found = true
                        }
                }
+               if found {
+                       pkg.Printf("type %s ", spec.Name)
+                       inter.Methods.List, methods = methods, inter.Methods.List
+                       err := format.Node(&pkg.buf, pkg.fs, inter)
+                       if err != nil {
+                               log.Fatal(err)
+                       }
+                       pkg.newlines(1)
+                       // Restore the original methods.
+                       inter.Methods.List = methods
+               }
        }
        return found
 }

diff --git a/src/cmd/doc/testdata/pkg.go b/src/cmd/doc/testdata/pkg.go
index d695bdf1c5f6bbf10419f6ad2925d3251877fee5..5ece8325651ebad4d2e39af1e67e1b8272992624 100644 (file)
--- a/src/cmd/doc/testdata/pkg.go
+++ b/src/cmd/doc/testdata/pkg.go
@@ -111,6 +111,13 @@ const unexportedTypedConstant ExportedType = 1 // In a separate section to test
 // Comment about exported interface.
 type ExportedInterface interface {
        // Comment before exported method.
+       //
+       //      // Code block showing how to use ExportedMethod
+       //      func DoSomething() error {
+       //              ExportedMethod()
+       //              return nil
+       //      }
+       //
        ExportedMethod()   // Comment on line with exported method.
        unexportedMethod() // Comment on line with unexported method.
        io.Reader          // Comment on line with embedded Reader.