From cb73169eeb58775f3a1a2b9c840e452897a49c79 Mon Sep 17 00:00:00 2001
From: bel <me@me.me>
Date: Mon, 20 Jan 2020 16:24:43 -0700
Subject: [PATCH] refactor and unit test filters

---
 server/ajax/task.go      | 43 +++++++++++++++++++------------------
 server/ajax/task_test.go | 46 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 21 deletions(-)

diff --git a/server/ajax/task.go b/server/ajax/task.go
index c98fedd..3750dfa 100755
--- a/server/ajax/task.go
+++ b/server/ajax/task.go
@@ -13,21 +13,25 @@ import (
 
 func (a *Ajax) loadTasks(w http.ResponseWriter, r *http.Request) error {
 	listID, _, _ := a.Cur(r)
-	filterComplete := func(t *task.Task) bool {
-		if form.Get(r, "compl") == "" {
-			return true
-		}
-		return form.Get(r, "compl") == "1" || !t.Complete
+	filterComplete := filterComplete(form.Get(r, "compl"))
+	filterTags := filterTags(form.ToStrArr(form.Get(r, "t")))
+	filterSubstr := filterSubstr(form.Get(r, "s"))
+	tasks, err := a.storageListTasks(listID, filterComplete, filterTags, filterSubstr)
+	if err != nil {
+		return err
 	}
-	filterTags := func(t *task.Task) bool {
-		if form.Get(r, "t") == "" {
-			return true
-		}
-		whitelistTags := form.ToStrArr(form.Get(r, "t"))
-		if len(whitelistTags) == 0 {
-			return true
-		}
-		for _, whitelisted := range whitelistTags {
+	return json.NewEncoder(w).Encode(map[string]interface{}{"list": tasks})
+}
+
+func filterComplete(compl string) func(t *task.Task) bool {
+	return func(t *task.Task) bool {
+		return compl == "" || (compl == "0" && !t.Complete) || (compl == "1" && t.Complete)
+	}
+}
+
+func filterTags(tags []string) func(t *task.Task) bool {
+	return func(t *task.Task) bool {
+		for _, whitelisted := range tags {
 			found := false
 			for _, tag := range t.Tags {
 				if whitelisted == tag {
@@ -40,15 +44,12 @@ func (a *Ajax) loadTasks(w http.ResponseWriter, r *http.Request) error {
 		}
 		return true
 	}
-	filterSubstr := func(t *task.Task) bool {
-		substr := form.Get(r, "s")
+}
+
+func filterSubstr(substr string) func(t *task.Task) bool {
+	return func(t *task.Task) bool {
 		return substr == "" || strings.Contains(fmt.Sprintf("%+v", t), substr)
 	}
-	tasks, err := a.storageListTasks(listID, filterComplete, filterTags, filterSubstr)
-	if err != nil {
-		return err
-	}
-	return json.NewEncoder(w).Encode(map[string]interface{}{"list": tasks})
 }
 
 func (a *Ajax) newTask(w http.ResponseWriter, r *http.Request) error {
diff --git a/server/ajax/task_test.go b/server/ajax/task_test.go
index 436c5b2..2f17728 100755
--- a/server/ajax/task_test.go
+++ b/server/ajax/task_test.go
@@ -2,6 +2,7 @@ package ajax
 
 import (
 	"encoding/json"
+	"local/todo-server/server/ajax/form"
 	"local/todo-server/server/ajax/task"
 	"net/http"
 	"net/http/httptest"
@@ -207,3 +208,48 @@ func TestAjaxChangeOrder(t *testing.T) {
 		t.Error(tasks[2])
 	}
 }
+
+func TestFilterComplete(t *testing.T) {
+	task := &task.Task{Complete: false}
+	cases := []struct {
+		query string
+		out   bool
+	}{
+		{query: "", out: true},
+		{query: "0", out: true},
+		{query: "1", out: false},
+	}
+
+	for name, c := range cases {
+		out := filterComplete(c.query)
+		if out(task) != c.out {
+			t.Errorf("[%d] want %v, got %v", name, c.out, out(task))
+		}
+	}
+}
+
+func TestFilterTags(t *testing.T) {
+	cases := map[string]struct {
+		query string
+		tags  []string
+		out   bool
+	}{
+		"no filter":                    {query: "", out: true},
+		"single matching filter":       {query: "a", out: true, tags: []string{"a"}},
+		"single non-matching filter":   {query: "a", out: false, tags: []string{"b"}},
+		"duo matching filter":          {query: "a, b", out: true, tags: []string{"b", "a"}},
+		"duo partial-matching filter":  {query: "a, c", out: false, tags: []string{"b", "a"}},
+		"duo non-matching filter":      {query: "a, c", out: false, tags: []string{"d", "e"}},
+		"trio matching filter":         {query: "a, b, c", out: true, tags: []string{"b", "a", "c", "d", "e"}},
+		"trio partial-matching filter": {query: "a, c, d", out: false, tags: []string{"b", "a", "d"}},
+		"trio non-matching filter":     {query: "a, b, c", out: false, tags: []string{"x", "y", "z"}},
+	}
+
+	for name, c := range cases {
+		task := &task.Task{Tags: c.tags}
+		out := filterTags(form.ToStrArr(c.query))
+		if v := out(task); v != c.out {
+			t.Errorf("[%s] want %v, got %v", name, c.out, v)
+		}
+	}
+}