v3: Fix trailing slash problems (goadesign#2560)

* Add trailing slash tests

* Fix trailing slash

* Fix a comment

* Add description to Path DSL

* Fix typo

dsl/http.go

@@ -224,6 +224,11 @@ func Produces(args ...string) {
 // description of the wildcard syntax). The corresponding parameters must be
 // described using Params. Multiple base paths may be defined for services.
 //
+// GET("/") does not add a trailing slash when the base path is defined by Path.
+// For example, when Path('foo') is defined, the path generated by GET("/") will be '/foo'.
+// As a special case, if you want to generate a path with a trailing slash, you can use
+// GET("/./") to generate a path such as '/foo/'.
+//
 // Path must appear in a API HTTP expression or a Service HTTP expression.
 //
 // Path accepts one argument: the HTTP path prefix.

expr/http_endpoint.go

@@ -888,7 +888,13 @@ func (r *RouteExpr) FullPaths() []string {
 	res := make([]string, len(bases))
 	for i, b := range bases {
 		res[i] = httppath.Clean(path.Join(b, r.Path))
-		if res[i] != "/" && strings.HasSuffix(r.Path, "/") {
+		if res[i] == "/" {
+			continue
+		}
+		// path has trailing slash
+		if r.Path == "/" && strings.HasSuffix(b, "/") {
+			res[i] += "/"
+		} else if r.Path != "/" && strings.HasSuffix(r.Path, "/") {
 			res[i] += "/"
 		}
 	}

expr/http_service.go

@@ -127,7 +127,12 @@ func (svc *HTTPServiceExpr) FullPaths() []string {
 			basePaths = []string{Root.API.HTTP.Path}
 		}
 		for _, base := range basePaths {
-			paths = append(paths, httppath.Clean(path.Join(base, p)))
+			v := httppath.Clean(path.Join(base, p))
+			// path has trailing slash
+			if strings.HasSuffix(p, "/") {
+				v += "/"
+			}
+			paths = append(paths, v)
 		}
 	}
 	return paths

http/codegen/paths_test.go

@@ -15,9 +15,7 @@ func TestPaths(t *testing.T) {
 		Code string
 	}{
 		{"single-path-no-param", testdata.PathNoParamDSL, testdata.PathNoParamCode},
-		{"single-path-no-param-trailing-slash", testdata.PathNoParamTrailingSlashDSL, testdata.PathNoParamTrailingSlashCode},
 		{"single-path-one-param", testdata.PathOneParamDSL, testdata.PathOneParamCode},
-		{"single-path-one-param-trailing-slash", testdata.PathOneParamTrailingSlashDSL, testdata.PathOneParamTrailingSlashCode},
 		{"single-path-multiple-params", testdata.PathMultipleParamsDSL, testdata.PathMultipleParamsCode},
 		{"alternative-paths", testdata.PathAlternativesDSL, testdata.PathAlternativesCode},
 		{"path-with-string-slice-param", testdata.PathStringSliceParamDSL, testdata.PathStringSliceParamCode},
@@ -48,3 +46,33 @@ func TestPaths(t *testing.T) {
 		})
 	}
 }
+
+func TestPathTrailingShash(t *testing.T) {
+	cases := []struct {
+		Name string
+		DSL  func()
+		Code string
+	}{
+		{"slash_with_base_path_no_trailing", testdata.BasePathNoTrailing_SlashWithBasePathNoTrailingDSL, testdata.BasePathNoTrailing_SlashWithBasePathNoTrailingCode},
+		{"trailing_with_base_path_no_trailing", testdata.BasePathNoTrailing_TrailingWithBasePathNoTrailingDSL, testdata.BasePathNoTrailing_TrailingWithBasePathNoTrailingCode},
+		{"slash_with_base_path_with_trailing", testdata.BasePathWithTrailingSlash_WithBasePathWithTrailingDSL, testdata.BasePathWithTrailingSlash_WithBasePathWithTrailingCode},
+		{"slash_no_base_path", testdata.NoBasePath_SlashNoBasePathDSL, testdata.NoBasePath_SlashNoBasePathCode},
+		{"path-trailing_no_base_path", testdata.NoBasePath_TrailingNoBasePathDSL, testdata.NoBasePath_TrailingNoBasePathCode},
+		{"add-trailing-slash-to-base-path", testdata.BasePath_SpecialTrailingSlashDSL, testdata.BasePath_SpecialTrailingSlashCode},
+	}
+
+	for _, c := range cases {
+		t.Run(c.Name, func(t *testing.T) {
+			RunHTTPDSL(t, c.DSL)
+			if len(expr.Root.API.HTTP.Services) != 1 {
+				t.Fatalf("got %d file(s), expected 1", len(expr.Root.API.HTTP.Services))
+			}
+			fs := serverPath(expr.Root.API.HTTP.Services[0])
+			sections := fs.SectionTemplates
+			code := codegen.SectionCode(t, sections[1])
+			if code != c.Code {
+				t.Errorf("invalid code, got:\n%s\ngot vs. expected:\n%s", code, codegen.Diff(t, code, c.Code))
+			}
+		})
+	}
+}

http/codegen/testdata/path_dsls.go

@@ -14,33 +14,84 @@ var PathNoParamDSL = func() {
 	})
 }
 
-var PathNoParamTrailingSlashDSL = func() {
-	Service("ServicePathNoParamTrailingSlash", func() {
-		Method("MethodPathNoParamTrailingSlash", func() {
+var BasePathNoTrailing_SlashWithBasePathNoTrailingDSL = func() {
+	Service("BasePathNoTrailing", func() {
+		HTTP(func() {
+			Path("foo")
+		})
+		Method("SlashWithBasePathNoTrailing", func() {
 			HTTP(func() {
-				GET("/one/two/")
+				GET("/")
 			})
 		})
 	})
 }
 
-var PathOneParamDSL = func() {
-	Service("ServicePathOneParam", func() {
-		Method("MethodPathOneParam", func() {
-			Payload(String)
+var BasePathNoTrailing_TrailingWithBasePathNoTrailingDSL = func() {
+	Service("BasePathNoTrailing", func() {
+		HTTP(func() {
+			Path("foo")
+		})
+		Method("TrailingWithBasePathNoTrailing", func() {
 			HTTP(func() {
-				GET("one/{a}/two")
+				GET("/bar/")
 			})
 		})
 	})
 }
 
-var PathOneParamTrailingSlashDSL = func() {
-	Service("ServicePathOneParamTrailingSlash", func() {
-		Method("MethodPathOneParamTrailingSlash", func() {
+var BasePathWithTrailingSlash_WithBasePathWithTrailingDSL = func() {
+	Service("BasePathWithTrailing", func() {
+		HTTP(func() {
+			Path("foo/")
+		})
+		Method("SlashWithBasePathWithTrailing", func() {
+			HTTP(func() {
+				GET("/")
+			})
+		})
+	})
+}
+
+var NoBasePath_SlashNoBasePathDSL = func() {
+	Service("NoBasePath", func() {
+		Method("SlashNoBasePath", func() {
+			HTTP(func() {
+				GET("/")
+			})
+		})
+	})
+}
+
+var NoBasePath_TrailingNoBasePathDSL = func() {
+	Service("NoBasePath", func() {
+		Method("TrailingNoBasePath", func() {
+			HTTP(func() {
+				GET("/foo/")
+			})
+		})
+	})
+}
+
+var BasePath_SpecialTrailingSlashDSL = func() {
+	Service("BasePath", func() {
+		HTTP(func() {
+			Path("/foo")
+		})
+		Method("SpecialTrailingSlash", func() {
+			HTTP(func() {
+				GET("/./")
+			})
+		})
+	})
+}
+
+var PathOneParamDSL = func() {
+	Service("ServicePathOneParam", func() {
+		Method("MethodPathOneParam", func() {
 			Payload(String)
 			HTTP(func() {
-				GET("one/{a}/")
+				GET("one/{a}/two")
 			})
 		})
 	})

http/codegen/testdata/path_functions.go

@@ -6,21 +6,45 @@ func MethodPathNoParamServicePathNoParamPath() string {
 }
 `
 
-var PathNoParamTrailingSlashCode = `// MethodPathNoParamTrailingSlashServicePathNoParamTrailingSlashPath returns the URL path to the ServicePathNoParamTrailingSlash service MethodPathNoParamTrailingSlash HTTP endpoint.
-func MethodPathNoParamTrailingSlashServicePathNoParamTrailingSlashPath() string {
-	return "/one/two/"
+var BasePathNoTrailing_SlashWithBasePathNoTrailingCode = `// SlashWithBasePathNoTrailingBasePathNoTrailingPath returns the URL path to the BasePathNoTrailing service SlashWithBasePathNoTrailing HTTP endpoint.
+func SlashWithBasePathNoTrailingBasePathNoTrailingPath() string {
+	return "/foo"
 }
 `
 
-var PathOneParamCode = `// MethodPathOneParamServicePathOneParamPath returns the URL path to the ServicePathOneParam service MethodPathOneParam HTTP endpoint.
-func MethodPathOneParamServicePathOneParamPath(a string) string {
-	return fmt.Sprintf("/one/%v/two", a)
+var BasePathNoTrailing_TrailingWithBasePathNoTrailingCode = `// TrailingWithBasePathNoTrailingBasePathNoTrailingPath returns the URL path to the BasePathNoTrailing service TrailingWithBasePathNoTrailing HTTP endpoint.
+func TrailingWithBasePathNoTrailingBasePathNoTrailingPath() string {
+	return "/foo/bar/"
+}
+`
+
+var BasePathWithTrailingSlash_WithBasePathWithTrailingCode = `// SlashWithBasePathWithTrailingBasePathWithTrailingPath returns the URL path to the BasePathWithTrailing service SlashWithBasePathWithTrailing HTTP endpoint.
+func SlashWithBasePathWithTrailingBasePathWithTrailingPath() string {
+	return "/foo/"
+}
+`
+
+var NoBasePath_SlashNoBasePathCode = `// SlashNoBasePathNoBasePathPath returns the URL path to the NoBasePath service SlashNoBasePath HTTP endpoint.
+func SlashNoBasePathNoBasePathPath() string {
+	return "/"
 }
 `
 
-var PathOneParamTrailingSlashCode = `// MethodPathOneParamTrailingSlashServicePathOneParamTrailingSlashPath returns the URL path to the ServicePathOneParamTrailingSlash service MethodPathOneParamTrailingSlash HTTP endpoint.
-func MethodPathOneParamTrailingSlashServicePathOneParamTrailingSlashPath(a string) string {
-	return fmt.Sprintf("/one/%v/", a)
+var NoBasePath_TrailingNoBasePathCode = `// TrailingNoBasePathNoBasePathPath returns the URL path to the NoBasePath service TrailingNoBasePath HTTP endpoint.
+func TrailingNoBasePathNoBasePathPath() string {
+	return "/foo/"
+}
+`
+
+var BasePath_SpecialTrailingSlashCode = `// SpecialTrailingSlashBasePathPath returns the URL path to the BasePath service SpecialTrailingSlash HTTP endpoint.
+func SpecialTrailingSlashBasePathPath() string {
+	return "/foo/"
+}
+`
+
+var PathOneParamCode = `// MethodPathOneParamServicePathOneParamPath returns the URL path to the ServicePathOneParam service MethodPathOneParam HTTP endpoint.
+func MethodPathOneParamServicePathOneParamPath(a string) string {
+	return fmt.Sprintf("/one/%v/two", a)
 }
 `
 

http/codegen/testdata/server_init_functions.go

@@ -17,7 +17,7 @@ func New(
 	return &Server{
 		Mounts: []*MountPoint{
 			{"MethodMultiEndpoints1", "GET", "/server_multi_endpoints/{id}"},
-			{"MethodMultiEndpoints2", "POST", "/server_multi_endpoints/"},
+			{"MethodMultiEndpoints2", "POST", "/server_multi_endpoints"},
 		},
 		MethodMultiEndpoints1: NewMethodMultiEndpoints1Handler(e.MethodMultiEndpoints1, mux, decoder, encoder, errhandler, formatter),
 		MethodMultiEndpoints2: NewMethodMultiEndpoints2Handler(e.MethodMultiEndpoints2, mux, decoder, encoder, errhandler, formatter),