Add support for user functions (#608)

* Add initial support for functions
* Show functions definitions
* Fix client tests
* Fix schema objects search
* Perform partial matching for functions
* Add function test
* Make sure to close client connections so that database could be dropped in tests
* Fix lint
* Allow to copy the view/functions definitions
* Nits

pkg/api/api.go

@@ -342,13 +342,21 @@ func GetSchemas(c *gin.Context) {
 
 // GetTable renders table information
 func GetTable(c *gin.Context) {
-	var res *client.Result
-	var err error
+	var (
+		res *client.Result
+		err error
+	)
 
-	if c.Request.FormValue("type") == client.ObjTypeMaterializedView {
-		res, err = DB(c).MaterializedView(c.Params.ByName("table"))
-	} else {
-		res, err = DB(c).Table(c.Params.ByName("table"))
+	db := DB(c)
+	tableName := c.Params.ByName("table")
+
+	switch c.Request.FormValue("type") {
+	case client.ObjTypeMaterializedView:
+		res, err = db.MaterializedView(tableName)
+	case client.ObjTypeFunction:
+		res, err = db.Function(tableName)
+	default:
+		res, err = db.Table(tableName)
 	}
 
 	serveResult(c, res, err)
@@ -541,3 +549,9 @@ func DataExport(c *gin.Context) {
 		badRequest(c, err)
 	}
 }
+
+// GetFunction renders function information
+func GetFunction(c *gin.Context) {
+	res, err := DB(c).Function(c.Param("id"))
+	serveResult(c, res, err)
+}

pkg/api/routes.go

@@ -42,6 +42,7 @@ func SetupRoutes(router *gin.Engine) {
 	api.GET("/tables/:table/info", GetTableInfo)
 	api.GET("/tables/:table/indexes", GetTableIndexes)
 	api.GET("/tables/:table/constraints", GetTableConstraints)
+	api.GET("/functions/:id", GetFunction)
 	api.GET("/query", RunQuery)
 	api.POST("/query", RunQuery)
 	api.GET("/explain", ExplainQuery)