add grouping functions tests

Author: hsldymq

funcs_grouping_test.go

@@ -0,0 +1,162 @@
+package handy
+
+import (
+    "fmt"
+    "slices"
+    "testing"
+)
+
+func TestJoin(t *testing.T) {
+    type student struct {
+        ID   string
+        Name string
+    }
+    type studentMajor struct {
+        ID    string
+        Major string
+    }
+
+    students := NewIterableFromSlice([]student{
+        {"1", "Alice"},
+        {"2", "Bob"},
+        {"3", "Cindy"},
+    })
+    majors := NewIterableFromSlice([]studentMajor{
+        {"1", "Math"},
+        {"1", "Physics"},
+        {"2", "English"},
+    })
+    e := Join(students, majors, func(s student) string {
+        return s.ID
+    }, func(m studentMajor) string {
+        return m.ID
+    })
+    type res struct {
+        ID    string
+        Name  string
+        Major string
+    }
+    actual := []res{}
+    for v := range e.Iter() {
+        actual = append(actual, res{
+            ID:    v.Outer.ID,
+            Name:  v.Outer.Name,
+            Major: v.Inner.Major,
+        })
+    }
+    expect := []res{
+        {"1", "Alice", "Math"},
+        {"1", "Alice", "Physics"},
+        {"2", "Bob", "English"},
+    }
+    if !slices.Equal(actual, expect) {
+        t.Fatalf("test Join, expect: %v, actual: %v", expect, actual)
+    }
+}
+
+func TestJoinAs(t *testing.T) {
+    type student struct {
+        ID   string
+        Name string
+    }
+    type studentMajor struct {
+        ID    string
+        Major string
+    }
+
+    type res struct {
+        ID    string
+        Name  string
+        Major string
+    }
+    students := NewIterableFromSlice([]student{
+        {"1", "Alice"},
+        {"2", "Bob"},
+        {"3", "Cindy"},
+    })
+    majors := NewIterableFromSlice([]studentMajor{
+        {"1", "Math"},
+        {"1", "Physics"},
+        {"2", "English"},
+    })
+    e := JoinAs(students, majors, func(s student) string {
+        return s.ID
+    }, func(m studentMajor) string {
+        return m.ID
+    }, func(outer student, inner studentMajor) res {
+        return res{
+            ID:    outer.ID,
+            Name:  outer.Name,
+            Major: inner.Major,
+        }
+    })
+    actual := []res{}
+    for v := range e.Iter() {
+        actual = append(actual, v)
+        if v.ID == "2" {
+            break
+        }
+    }
+    expect := []res{
+        {"1", "Alice", "Math"},
+        {"1", "Alice", "Physics"},
+        {"2", "Bob", "English"},
+    }
+    if !slices.Equal(actual, expect) {
+        t.Fatalf("test JoinAs, expect: %v, actual: %v", expect, actual)
+    }
+}
+
+func TestGroupJoin(t *testing.T) {
+    type student struct {
+        ID   string
+        Name string
+    }
+    type studentMajor struct {
+        ID    string
+        Major string
+    }
+
+    students := NewIterableFromSlice([]student{
+        {"1", "Alice"},
+        {"2", "Bob"},
+        {"3", "Cindy"},
+    })
+    majors := NewIterableFromSlice([]studentMajor{
+        {"1", "Math"},
+        {"1", "Physics"},
+        {"2", "English"},
+    })
+    e := GroupJoin(students, majors, func(s student) string {
+        return s.ID
+    }, func(m studentMajor) string {
+        return m.ID
+    })
+    type res struct {
+        ID     string
+        Name   string
+        Majors string
+    }
+    actual := []res{}
+    for v := range e.Iter() {
+        r := res{
+            ID:   v.Outer.ID,
+            Name: v.Outer.Name,
+        }
+        for s := range v.Inner.Iter() {
+            if r.Majors != "" {
+                r.Majors += fmt.Sprintf(",%s", s.Major)
+            } else {
+                r.Majors = s.Major
+            }
+        }
+        actual = append(actual, r)
+    }
+    expect := []res{
+        {"1", "Alice", "Math,Physics"},
+        {"2", "Bob", "English"},
+    }
+    if !slices.Equal(actual, expect) {
+        t.Fatalf("test Join, expect: %v, actual: %v", expect, actual)
+    }
+}