improve patch callback in migrations

.github/workflows/test.yml

@@ -0,0 +1,47 @@
+name: Test
+
+on:
+  pull_request:
+    branches:
+      - develop
+  push:
+    branches:
+      - develop
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: ^1.21.0
+
+      - name: Display Go version
+        run: go version
+
+      - name: Install dependencies
+        run: go get
+
+      - name: Run tests
+        run: go test -v
+
+  notify:
+    name: Send Discord workflow notification
+    runs-on: ubuntu-latest
+    needs: test
+    steps:
+      - name: Send notification
+        uses: annybs/action-notify-discord@v1
+        if: ${{ always() }}
+        with:
+          repository: ${{ github.repository }}
+          result: ${{ needs.test.result }}
+          run-id: ${{ github.run_id }}
+          run-number: ${{ github.run_number }}
+          webhook-url: ${{ secrets.DISCORD_WEBHOOK }}
+          workflow: ${{ github.workflow }}

.gitignore

@@ -0,0 +1 @@
+go.sum

LICENSE.md

@@ -1,6 +1,6 @@
 # MIT License
 
-Copyright © 2024 Aneurin Barker Snook a@aneur.in
+Copyright © 2026 Aneurin Barker Snook a@aneur.in
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

README.md

@@ -4,4 +4,4 @@ A simple library for parsing and comparing versions according to [Semantic Versi
 
 ## License
 
-See [LICENSE.md](../LICENSE.md)
+See [LICENSE.md](./LICENSE.md)

constraint.go

@@ -0,0 +1,9 @@
+package version
+
+// Constraint enables matching a version based on lower and upper bounds.
+type Constraint struct {
+	Gt  *Version // Greater than...
+	Gte *Version // Greater than or equal to...
+	Lt  *Version // Less than...
+	Lte *Version // Less than or equal to...
+}

error.go

@@ -2,17 +2,17 @@ package version
 
 import "fmt"
 
+// Version error.
+var (
+	ErrInvalidVersion = Error{Message: "invalid version %q"}
+)
+
 // Error represents a version error.
 type Error struct {
 	Message string
 	Version string
 }
 
-// Version error.
-var (
-	ErrInvalidVersion = Error{Message: "invalid version %q"}
-)
-
 // Error retrieves the message of a REST API error.
 func (e Error) Error() string {
 	return fmt.Sprintf(e.Message, e.Version)

go.mod

@@ -1,3 +1,3 @@
-module github.com/annybs/go/version
+module code.aneur.in/go/version
 
 go 1.21

list.go

@@ -3,6 +3,27 @@ package version
 // List is a slice of versions that implements sort.Interface.
 type List []*Version
 
+// Match tests versions against a constraint and returns a new List of matching versions only.
+func (list List) Match(constraints ...*Constraint) List {
+	filtered := List{}
+
+	for _, v := range list {
+		ok := true
+		for _, c := range constraints {
+			if !v.Match(c) {
+				ok = false
+				break
+			}
+		}
+
+		if ok {
+			filtered = append(filtered, v)
+		}
+	}
+
+	return filtered
+}
+
 func (list List) Len() int {
 	return len(list)
 }

list_test.go

@@ -47,3 +47,51 @@ func TestListSort(t *testing.T) {
 		}
 	}
 }
+
+func TestList_Match(t *testing.T) {
+	type TestCase struct {
+		Input      List
+		Constraint *Constraint
+		Expected   List
+	}
+
+	testCases := []TestCase{
+		{
+			Input:    List{MustParse("1.0.0"), MustParse("1.1.0"), MustParse("2.0.2"), MustParse("3.4.5")},
+			Expected: List{MustParse("1.0.0"), MustParse("1.1.0"), MustParse("2.0.2"), MustParse("3.4.5")},
+		},
+		{
+			Input:      List{MustParse("1.0.0"), MustParse("1.1.0"), MustParse("2.0.2"), MustParse("3.4.5")},
+			Constraint: &Constraint{Gt: MustParse("1.0.0")},
+			Expected:   List{MustParse("1.1.0"), MustParse("2.0.2"), MustParse("3.4.5")},
+		},
+		{
+			Input:      List{MustParse("1.0.0"), MustParse("1.1.0"), MustParse("2.0.2"), MustParse("3.4.5")},
+			Constraint: &Constraint{Lt: MustParse("3.0.0")},
+			Expected:   List{MustParse("1.0.0"), MustParse("1.1.0"), MustParse("2.0.2")},
+		},
+		{
+			Input:      List{MustParse("1.0.0"), MustParse("1.1.0"), MustParse("2.0.2"), MustParse("3.4.5")},
+			Constraint: &Constraint{Gte: MustParse("2.0.2")},
+			Expected:   List{MustParse("2.0.2"), MustParse("3.4.5")},
+		},
+	}
+
+	for i, testCase := range testCases {
+		actual := testCase.Input.Match(testCase.Constraint)
+
+		ok := true
+		for j, v := range actual {
+			expected := testCase.Expected[j]
+			cmp := v.Compare(expected)
+			if cmp != 0 {
+				ok = false
+				t.Errorf("test %d failed at position %d (expected %s, got %s)", i, j, expected, actual)
+			}
+		}
+
+		if ok {
+			t.Logf("test %d passed", i)
+		}
+	}
+}

migration.go

@@ -0,0 +1,103 @@
+package version
+
+import (
+	"sort"
+)
+
+// AfterPatchCallback is called after each time a migration is successfully applied (up) or reverted (down).
+type AfterPatchCallback func(applied, next *Version)
+
+// Migration maps provide a simple way to store and run versioned 'patch' functions.
+type Migration map[string]Patch
+
+// Down reverts all patches in reverse version order.
+func (m Migration) Down(after AfterPatchCallback) error {
+	versions, err := m.Versions()
+	if err != nil {
+		return err
+	}
+
+	for i := len(versions); i > 0; i-- {
+		v := versions[i-1]
+		patch := m[v.Text]
+		if err := patch.Down(); err != nil {
+			return err
+		}
+
+		if after != nil {
+			var next *Version
+			if i > 1 {
+				next = versions[i-1]
+			}
+
+			after(v, next)
+		}
+	}
+
+	return nil
+}
+
+// Match tests versions against a constraint and returns a new migration map of matching versions only.
+func (m Migration) Match(constraints ...*Constraint) (Migration, error) {
+	l, err := m.Versions()
+	if err != nil {
+		return nil, err
+	}
+
+	l = l.Match(constraints...)
+
+	m2 := Migration{}
+	for _, v := range l {
+		m2[v.Text] = m[v.Text]
+	}
+
+	return m2, nil
+}
+
+// Up executes all patches in version order.
+func (m Migration) Up(after AfterPatchCallback) error {
+	versions, err := m.Versions()
+	if err != nil {
+		return err
+	}
+
+	for i, v := range versions {
+		patch := m[v.Text]
+		if err := patch.Up(); err != nil {
+			return err
+		}
+
+		if after != nil {
+			var next *Version
+			if i < len(versions)-1 {
+				next = versions[i+1]
+			}
+
+			after(v, next)
+		}
+	}
+
+	return nil
+}
+
+// Versions returns a List of all versions in the migration map.
+func (m Migration) Versions() (List, error) {
+	l := List{}
+	for str := range m {
+		v, err := Parse(str)
+		if err != nil {
+			return nil, err
+		}
+
+		l = append(l, v)
+	}
+
+	sort.Stable(l)
+
+	return l, nil
+}
+
+type Patch struct {
+	Down func() error
+	Up   func() error
+}

version.go

@@ -19,7 +19,11 @@ type Version struct {
 //
 // Extensions such as pre-release version or build metadata are ignored when comparing versions.
 func (a *Version) Compare(b *Version) int {
-	if a == nil || b == nil {
+	if a == nil && b != nil {
+		return -1
+	} else if a != nil && b == nil {
+		return 1
+	} else if a == nil && b == nil {
 		return 0
 	}
 
@@ -40,6 +44,47 @@ func (a *Version) Compare(b *Version) int {
 	return -1
 }
 
+// Equal checks for equality between two versions.
+//
+// Extensions such as pre-release version or build metadata are ignored when comparing versions.
+func (a *Version) Equal(b *Version) bool {
+	return a.Compare(b) == 0
+}
+
+// Match tests the version against a constraint.
+// Gt and Lt take precedence over Gte and Lte.
+func (v *Version) Match(c *Constraint) bool {
+	if v == nil {
+		return false
+	}
+
+	if c == nil {
+		return true
+	}
+
+	if c.Gt != nil {
+		if v.Compare(c.Gt) <= 0 {
+			return false
+		}
+	} else if c.Gte != nil {
+		if v.Compare(c.Gte) < 0 {
+			return false
+		}
+	}
+
+	if c.Lt != nil {
+		if v.Compare(c.Lt) >= 0 {
+			return false
+		}
+	} else if c.Lte != nil {
+		if v.Compare(c.Lte) > 0 {
+			return false
+		}
+	}
+
+	return true
+}
+
 // Less performs a simple comparison of this version (a) with another version (b).
 // This function returns true if a is less than b, or false otherwise.
 //

version_test.go

@@ -55,8 +55,8 @@ func TestVersion_Compare(t *testing.T) {
 		{A: MustParse("1.20.0"), B: MustParse("1.2.0"), Expected: 1},
 		{A: MustParse("1.20.0"), B: MustParse("1.2.20"), Expected: 1},
 		{A: MustParse("1.20.0"), B: MustParse("1.20.1"), Expected: -1},
-		{A: MustParse("1.0.0"), Expected: 0},
+		{A: MustParse("1.0.0"), Expected: 1},
-		{B: MustParse("1.0.0"), Expected: 0},
+		{B: MustParse("1.0.0"), Expected: -1},
 		{Expected: 0},
 	}
 
@@ -102,3 +102,84 @@ func TestVersion_Less(t *testing.T) {
 		}
 	}
 }
+
+func TestVersion_Match(t *testing.T) {
+	type TestCase struct {
+		V        *Version
+		C        *Constraint
+		Expected bool
+	}
+
+	testCases := []TestCase{
+		{V: MustParse("1.0.0"), Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("0.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("0.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.0.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Lt: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Lt: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Lt: MustParse("1.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Lte: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Lte: MustParse("1.0.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Lte: MustParse("1.1.0")}, Expected: true},
+
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("0.1.0"), Lt: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("0.1.0"), Lt: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("0.1.0"), Lt: MustParse("1.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.0.0"), Lt: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.0.0"), Lt: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.0.0"), Lt: MustParse("1.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.1.0"), Lt: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.1.0"), Lt: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.1.0"), Lt: MustParse("1.1.0")}, Expected: false},
+
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("0.1.0"), Lte: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("0.1.0"), Lte: MustParse("1.0.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("0.1.0"), Lte: MustParse("1.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.0.0"), Lte: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.0.0"), Lte: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.0.0"), Lte: MustParse("1.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.1.0"), Lte: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.1.0"), Lte: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.1.0"), Lte: MustParse("1.1.0")}, Expected: false},
+
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("0.1.0"), Lt: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("0.1.0"), Lt: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("0.1.0"), Lt: MustParse("1.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.0.0"), Lt: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.0.0"), Lt: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.0.0"), Lt: MustParse("1.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.1.0"), Lt: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.1.0"), Lt: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.1.0"), Lt: MustParse("1.1.0")}, Expected: false},
+
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("0.1.0"), Lte: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("0.1.0"), Lte: MustParse("1.0.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("0.1.0"), Lte: MustParse("1.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.0.0"), Lte: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.0.0"), Lte: MustParse("1.0.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.0.0"), Lte: MustParse("1.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.1.0"), Lte: MustParse("0.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.1.0"), Lte: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gte: MustParse("1.1.0"), Lte: MustParse("1.1.0")}, Expected: false},
+
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.0.0"), Gte: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("0.1.0"), Gte: MustParse("1.1.0")}, Expected: true},
+		{V: MustParse("1.0.0"), C: &Constraint{Gt: MustParse("1.1.0"), Gte: MustParse("0.1.0")}, Expected: false},
+
+		{V: MustParse("1.0.0"), C: &Constraint{Lt: MustParse("1.0.0"), Lte: MustParse("1.0.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Lt: MustParse("0.1.0"), Lte: MustParse("1.1.0")}, Expected: false},
+		{V: MustParse("1.0.0"), C: &Constraint{Lt: MustParse("1.1.0"), Lte: MustParse("0.1.0")}, Expected: true},
+	}
+
+	for i, testCase := range testCases {
+		actual := testCase.V.Match(testCase.C)
+		if actual != testCase.Expected {
+			t.Errorf("test %d failed (expected %v, actual %v)", i, testCase.Expected, actual)
+		} else {
+			t.Logf("test %d passed with %v", i, actual)
+		}
+	}
+}