[TT-1944] Fix regex matching for parameters (#6480)

JIRA: https://tyktech.atlassian.net/browse/TT-1944

Match used `*` allowing it to match 0 characters.
Match now uses `+`, matching a minimum of 1 character.

Behaviour change:

Previously requests for `/users/{id}` would allow `/users/` to pass
without parameter.
When replacing named parameter patterns, `{}` would be matched, which is
invalid.

Follow up issue:

Mux can define a regex as `{id:[0-9]+}` or similar custom regex rules.
The match does not respect this.

---------

Co-authored-by: Tit Petric <tit@tyk.io>

.taskfiles/test.yml

@@ -51,7 +51,7 @@ tasks:
       - for: { var: packages, as: package }
         cmd: |-
           gotestsum --no-color=false --hide-summary=skipped --raw-command \
-          go test -p 1 -json {{.testArgs}} {{.args}} -count=1 -v \
+          go test -p 1 -parallel 1 -json {{.testArgs}} {{.args}} -count=1 -v \
           -coverprofile=coverage/{{.package | replace "." "gateway" | replace "/" "-"}}.cov {{.package}} | head -n -2
 
   integration-combined:
@@ -66,7 +66,7 @@ tasks:
       - defer: { task: services:down }
       - defer: { task: report }
       - rm -rf coverage && mkdir -p coverage
-      - go test -p 1 -json {{.testArgs}} {{.args}} -coverprofile=coverage/{{.product}}-all.cov -count=1 -v ./... > coverage/{{.product}}-all.json
+      - go test -p 1 -parallel 1 -json {{.testArgs}} {{.args}} -coverprofile=coverage/{{.product}}-all.cov -count=1 -v ./... > coverage/{{.product}}-all.json
 
   plugin:race:
     dir: '{{.dir}}'

gateway/api_definition.go

@@ -817,13 +817,18 @@ func (a APIDefinitionLoader) getPathSpecs(apiVersionDef apidef.VersionInfo, conf
 	return combinedPath, len(whiteListPaths) > 0
 }
 
+// match mux tags, `{id}`.
+var apiLangIDsRegex = regexp.MustCompile(`{([^}]+)}`)
+
 func (a APIDefinitionLoader) generateRegex(stringSpec string, newSpec *URLSpec, specType URLStatus, conf config.Config) {
-	apiLangIDsRegex := regexp.MustCompile(`{([^}]*)}`)
-	asRegexStr := apiLangIDsRegex.ReplaceAllString(stringSpec, `([^/]*)`)
+	// replace mux named parameters with regex path match
+	asRegexStr := apiLangIDsRegex.ReplaceAllString(stringSpec, `([^/]+)`)
+
 	// Case insensitive match
 	if newSpec.IgnoreCase || conf.IgnoreEndpointCase {
 		asRegexStr = "(?i)" + asRegexStr
 	}
+
 	asRegex, _ := regexp.Compile(asRegexStr)
 	newSpec.Status = specType
 	newSpec.Spec = asRegex

gateway/api_definition_test.go

@@ -106,7 +106,7 @@ func TestWhitelist(t *testing.T) {
 
 		ts.Run(t, []test.TestCase{
 			// Should mock path
-			{Path: "/reply/", Code: http.StatusOK, BodyMatch: "flump"},
+			{Path: "/reply/", Code: http.StatusForbidden},
 			{Path: "/reply/123", Code: http.StatusOK, BodyMatch: "flump"},
 			// Should get original upstream response
 			{Path: "/get", Code: http.StatusOK, BodyMatch: `"Url":"/get"`},
@@ -147,14 +147,14 @@ func TestWhitelist(t *testing.T) {
 
 		ts.Run(t, []test.TestCase{
 			{Path: "/foo", Code: http.StatusForbidden},
-			{Path: "/foo/", Code: http.StatusOK},
+			{Path: "/foo/", Code: http.StatusForbidden},
 			{Path: "/foo/1", Code: http.StatusOK},
 			{Path: "/foo/1/bar", Code: http.StatusForbidden},
-			{Path: "/foo/1/bar/", Code: http.StatusOK},
+			{Path: "/foo/1/bar/", Code: http.StatusForbidden},
 			{Path: "/foo/1/bar/1", Code: http.StatusOK},
 			{Path: "/", Code: http.StatusForbidden},
 			{Path: "/baz", Code: http.StatusForbidden},
-			{Path: "/baz/", Code: http.StatusOK},
+			{Path: "/baz/", Code: http.StatusForbidden},
 			{Path: "/baz/1", Code: http.StatusOK},
 			{Path: "/baz/1/", Code: http.StatusOK},
 			{Path: "/baz/1/bazz", Code: http.StatusOK},