[🤖] Add Unit-Tests

2026-04-27 10:46:08 +02:00
parent dad0e3240d
commit 02d6894ec6
116 changed files with 18795 additions and 1 deletions
@@ -0,0 +1,160 @@
+package bfcodegen
+
+import (
+	"git.blackforestbytes.com/BlackForestBytes/goext/langext"
+	"git.blackforestbytes.com/BlackForestBytes/goext/tst"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestProcessCSIDFileSimple(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package mymodels
+
+type UserID string // @csid:type [USR]
+type OrderID string // @csid:type [ORD]
+`
+	fp := writeTestFile(t, dir, "models.go", src)
+
+	ids, pkg, err := processCSIDFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, pkg, "mymodels")
+	tst.AssertEqual(t, len(ids), 2)
+	tst.AssertEqual(t, ids[0].Name, "UserID")
+	tst.AssertEqual(t, ids[0].Prefix, "USR")
+	tst.AssertEqual(t, ids[1].Name, "OrderID")
+	tst.AssertEqual(t, ids[1].Prefix, "ORD")
+	tst.AssertEqual(t, ids[0].FileRelative, "models.go")
+}
+
+func TestProcessCSIDFilePrefixMustBeUppercase(t *testing.T) {
+	dir := t.TempDir()
+
+	// lowercase prefix should not match the regex (only [A-Z0-9]{3})
+	src := `package x
+
+type FooID string // @csid:type [usr]
+`
+	fp := writeTestFile(t, dir, "x.go", src)
+
+	ids, pkg, err := processCSIDFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, pkg, "x")
+	tst.AssertEqual(t, len(ids), 0)
+}
+
+func TestProcessCSIDFileGeneratedHeaderSkipped(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `// Code generated by csid-generate.go DO NOT EDIT.
+
+package x
+
+type SkipMeID string // @csid:type [SKP]
+`
+	fp := writeTestFile(t, dir, "skip.go", src)
+
+	ids, pkg, err := processCSIDFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, pkg, "")
+	tst.AssertEqual(t, len(ids), 0)
+}
+
+func TestGenerateCharsetIDSpecsEndToEnd(t *testing.T) {
+	dir := t.TempDir()
+
+	src1 := `package models
+
+type EntityID string // @csid:type [ENT]
+type UserID string // @csid:type [USR]
+`
+	writeTestFile(t, dir, "a_models.go", src1)
+
+	src2 := `package models
+
+type OrderID string // @csid:type [ORD]
+`
+	writeTestFile(t, dir, "b_models.go", src2)
+
+	dest := filepath.Join(dir, "csid_gen.go")
+
+	err := GenerateCharsetIDSpecs(dir, dest, CSIDGenOptions{DebugOutput: langext.PFalse})
+	tst.AssertNoErr(t, err)
+
+	out, err := os.ReadFile(dest)
+	tst.AssertNoErr(t, err)
+	outStr := string(out)
+
+	tst.AssertTrue(t, strings.Contains(outStr, "package models"))
+	tst.AssertTrue(t, strings.Contains(outStr, "ChecksumCharsetIDGenerator"))
+	tst.AssertTrue(t, strings.Contains(outStr, "func NewUserID()"))
+	tst.AssertTrue(t, strings.Contains(outStr, "func NewOrderID()"))
+	tst.AssertTrue(t, strings.Contains(outStr, "func NewEntityID()"))
+	tst.AssertTrue(t, strings.Contains(outStr, `prefixUserID`) && strings.Contains(outStr, `"USR"`))
+	tst.AssertTrue(t, strings.Contains(outStr, `prefixOrderID`) && strings.Contains(outStr, `"ORD"`))
+	tst.AssertTrue(t, strings.Contains(outStr, `prefixEntityID`) && strings.Contains(outStr, `"ENT"`))
+}
+
+func TestGenerateCharsetIDSpecsIdempotentWhenUnchanged(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package models
+
+type SomeID string // @csid:type [SOM]
+`
+	writeTestFile(t, dir, "models.go", src)
+	dest := filepath.Join(dir, "csid_gen.go")
+
+	err := GenerateCharsetIDSpecs(dir, dest, CSIDGenOptions{})
+	tst.AssertNoErr(t, err)
+
+	content1, err := os.ReadFile(dest)
+	tst.AssertNoErr(t, err)
+
+	err = GenerateCharsetIDSpecs(dir, dest, CSIDGenOptions{})
+	tst.AssertNoErr(t, err)
+
+	content2, err := os.ReadFile(dest)
+	tst.AssertNoErr(t, err)
+
+	tst.AssertEqual(t, string(content1), string(content2))
+}
+
+func TestGenerateCharsetIDSpecsErrorsWithoutPackage(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `// Code generated by csid-generate.go DO NOT EDIT.
+
+package x
+
+type SkippedID string // @csid:type [SKP]
+`
+	writeTestFile(t, dir, "z.go", src)
+	dest := filepath.Join(dir, "csid_gen.go")
+
+	err := GenerateCharsetIDSpecs(dir, dest, CSIDGenOptions{})
+	tst.AssertTrue(t, err != nil)
+}
+
+func TestGenerateCharsetIDSpecsMissingDir(t *testing.T) {
+	dir := filepath.Join(t.TempDir(), "definitely-missing")
+	err := GenerateCharsetIDSpecs(dir, filepath.Join(dir, "csid_gen.go"), CSIDGenOptions{})
+	tst.AssertTrue(t, err != nil)
+}
+
+func TestFmtCSIDOutputContainsAllNames(t *testing.T) {
+	ids := []CSIDDef{
+		{File: "a.go", FileRelative: "a.go", Name: "AlphaID", Prefix: "ALP"},
+		{File: "b.go", FileRelative: "b.go", Name: "BetaID", Prefix: "BET"},
+	}
+	out := fmtCSIDOutput("CHK_XYZ", ids, "models")
+	tst.AssertTrue(t, strings.Contains(out, "package models"))
+	tst.AssertTrue(t, strings.Contains(out, "CHK_XYZ"))
+	tst.AssertTrue(t, strings.Contains(out, "AlphaID"))
+	tst.AssertTrue(t, strings.Contains(out, "BetaID"))
+	tst.AssertTrue(t, strings.Contains(out, `prefixAlphaID`) && strings.Contains(out, `"ALP"`))
+	tst.AssertTrue(t, strings.Contains(out, `prefixBetaID`) && strings.Contains(out, `"BET"`))
+}
@@ -0,0 +1,369 @@
+package bfcodegen
+
+import (
+	"git.blackforestbytes.com/BlackForestBytes/goext/langext"
+	"git.blackforestbytes.com/BlackForestBytes/goext/tst"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestProcessEnumFileBasicStringEnum(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package mymodels
+
+type Color string // @enum:type
+
+const (
+	ColorRed   Color = "red"
+	ColorBlue  Color = "blue"
+	ColorGreen Color = "green"
+)
+`
+	fp := writeTestFile(t, dir, "color.go", src)
+
+	enums, pkg, err := processEnumFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, pkg, "mymodels")
+	tst.AssertEqual(t, len(enums), 1)
+	tst.AssertEqual(t, enums[0].EnumTypeName, "Color")
+	tst.AssertEqual(t, enums[0].Type, "string")
+	tst.AssertEqual(t, len(enums[0].Values), 3)
+	tst.AssertEqual(t, enums[0].Values[0].VarName, "ColorRed")
+	tst.AssertEqual(t, enums[0].Values[0].Value, `"red"`)
+	tst.AssertEqual(t, enums[0].Values[1].VarName, "ColorBlue")
+	tst.AssertEqual(t, enums[0].Values[2].VarName, "ColorGreen")
+}
+
+func TestProcessEnumFileIntEnum(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package m
+
+type Priority int // @enum:type
+
+const (
+	PriorityLow    Priority = 0
+	PriorityMedium Priority = 1
+	PriorityHigh   Priority = 2
+)
+`
+	fp := writeTestFile(t, dir, "prio.go", src)
+
+	enums, pkg, err := processEnumFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, pkg, "m")
+	tst.AssertEqual(t, len(enums), 1)
+	tst.AssertEqual(t, enums[0].EnumTypeName, "Priority")
+	tst.AssertEqual(t, enums[0].Type, "int")
+	tst.AssertEqual(t, len(enums[0].Values), 3)
+	tst.AssertEqual(t, enums[0].Values[0].Value, "0")
+	tst.AssertEqual(t, enums[0].Values[2].Value, "2")
+}
+
+func TestProcessEnumFileWithDescriptions(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package m
+
+type Status string // @enum:type
+
+const (
+	StatusActive   Status = "active"   // The active status
+	StatusInactive Status = "inactive" // The inactive status
+)
+`
+	fp := writeTestFile(t, dir, "s.go", src)
+
+	enums, _, err := processEnumFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, len(enums), 1)
+	tst.AssertEqual(t, len(enums[0].Values), 2)
+
+	v0 := enums[0].Values[0]
+	tst.AssertTrue(t, v0.Description != nil)
+	tst.AssertEqual(t, *v0.Description, "The active status")
+	tst.AssertTrue(t, v0.Data == nil)
+}
+
+func TestProcessEnumFileWithDataComment(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package m
+
+type Severity string // @enum:type
+
+const (
+	SeverityLow  Severity = "low"  // {"description": "Low severity", "weight": 1}
+	SeverityHigh Severity = "high" // {"description": "High severity", "weight": 9}
+)
+`
+	fp := writeTestFile(t, dir, "sev.go", src)
+
+	enums, _, err := processEnumFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, len(enums), 1)
+	tst.AssertEqual(t, len(enums[0].Values), 2)
+
+	v0 := enums[0].Values[0]
+	tst.AssertTrue(t, v0.Data != nil)
+	tst.AssertTrue(t, v0.Description != nil)
+	tst.AssertEqual(t, *v0.Description, "Low severity")
+}
+
+func TestProcessEnumFileNonMatchingValuesNotAttached(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package m
+
+type Color string // @enum:type
+
+const (
+	ColorRed Color = "red"
+)
+
+const (
+	OtherX OtherType = "x"
+)
+`
+	fp := writeTestFile(t, dir, "c.go", src)
+
+	enums, _, err := processEnumFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, len(enums), 1)
+	tst.AssertEqual(t, len(enums[0].Values), 1)
+	tst.AssertEqual(t, enums[0].Values[0].VarName, "ColorRed")
+}
+
+func TestProcessEnumFileGeneratedHeaderSkipped(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `// Code generated by enum-generate.go DO NOT EDIT.
+
+package x
+
+type Foo string // @enum:type
+`
+	fp := writeTestFile(t, dir, "skip.go", src)
+
+	enums, pkg, err := processEnumFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, pkg, "")
+	tst.AssertEqual(t, len(enums), 0)
+}
+
+func TestTryParseDataCommentValid(t *testing.T) {
+	m, ok := tryParseDataComment(`{"description": "hello", "weight": 5}`)
+	tst.AssertTrue(t, ok)
+	descr, _ := m["description"].(string)
+	tst.AssertEqual(t, descr, "hello")
+	weight, _ := m["weight"].(float64)
+	tst.AssertEqual(t, weight, float64(5))
+}
+
+func TestTryParseDataCommentBool(t *testing.T) {
+	m, ok := tryParseDataComment(`{"a": true, "b": false}`)
+	tst.AssertTrue(t, ok)
+	a, _ := m["a"].(bool)
+	tst.AssertTrue(t, a)
+	b, _ := m["b"].(bool)
+	tst.AssertFalse(t, b)
+}
+
+func TestTryParseDataCommentRejectsNull(t *testing.T) {
+	// null becomes a nil interface — its reflect.Kind is Invalid, not Pointer,
+	// so it does not match any of the allowed kinds and is rejected.
+	_, ok := tryParseDataComment(`{"x": null}`)
+	tst.AssertFalse(t, ok)
+}
+
+func TestTryParseDataCommentInvalidJSON(t *testing.T) {
+	_, ok := tryParseDataComment(`{not valid json}`)
+	tst.AssertFalse(t, ok)
+}
+
+func TestTryParseDataCommentRejectsArrays(t *testing.T) {
+	// arrays as values are not in the supported kinds list
+	_, ok := tryParseDataComment(`{"x": [1, 2, 3]}`)
+	tst.AssertFalse(t, ok)
+}
+
+func TestTryParseDataCommentRejectsObjects(t *testing.T) {
+	_, ok := tryParseDataComment(`{"x": {"nested": 1}}`)
+	tst.AssertFalse(t, ok)
+}
+
+func TestGenerateEnumSpecsEndToEnd(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package models
+
+type Color string // @enum:type
+
+const (
+	ColorRed   Color = "red"
+	ColorGreen Color = "green"
+	ColorBlue  Color = "blue"
+)
+`
+	writeTestFile(t, dir, "color.go", src)
+	dest := filepath.Join(dir, "enum_gen.go")
+
+	err := GenerateEnumSpecs(dir, dest, EnumGenOptions{
+		DebugOutput: langext.PFalse,
+		GoFormat:    langext.PTrue,
+	})
+	tst.AssertNoErr(t, err)
+
+	out, err := os.ReadFile(dest)
+	tst.AssertNoErr(t, err)
+	outStr := string(out)
+
+	tst.AssertTrue(t, strings.Contains(outStr, "package models"))
+	tst.AssertTrue(t, strings.Contains(outStr, "ChecksumEnumGenerator"))
+	tst.AssertTrue(t, strings.Contains(outStr, "ParseColor"))
+	tst.AssertTrue(t, strings.Contains(outStr, "ColorValues"))
+	tst.AssertTrue(t, strings.Contains(outStr, "ColorRed"))
+	tst.AssertTrue(t, strings.Contains(outStr, "ColorBlue"))
+	tst.AssertTrue(t, strings.Contains(outStr, "ColorGreen"))
+}
+
+func TestGenerateEnumSpecsDeterministic(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package models
+
+type Status string // @enum:type
+
+const (
+	StatusActive Status = "active" // The active one
+	StatusOff    Status = "off"    // The off one
+)
+`
+	writeTestFile(t, dir, "s.go", src)
+
+	s1, cs1, changed1, err := _generateEnumSpecs(dir, "", "N/A", true, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertTrue(t, changed1)
+
+	s2, cs2, changed2, err := _generateEnumSpecs(dir, "", "N/A", true, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertTrue(t, changed2)
+
+	tst.AssertEqual(t, cs1, cs2)
+	tst.AssertEqual(t, s1, s2)
+}
+
+func TestGenerateEnumSpecsNoChangeWhenChecksumMatches(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package models
+
+type Status string // @enum:type
+
+const (
+	StatusActive Status = "active"
+)
+`
+	writeTestFile(t, dir, "s.go", src)
+
+	_, cs, changed, err := _generateEnumSpecs(dir, "", "N/A", true, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertTrue(t, changed)
+
+	s2, cs2, changed2, err := _generateEnumSpecs(dir, "", cs, true, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertFalse(t, changed2)
+	tst.AssertEqual(t, cs2, cs)
+	tst.AssertEqual(t, s2, "")
+}
+
+func TestGenerateEnumSpecsWithoutGoFormat(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package models
+
+type Color string // @enum:type
+
+const (
+	ColorRed Color = "red"
+)
+`
+	writeTestFile(t, dir, "c.go", src)
+
+	out, _, _, err := _generateEnumSpecs(dir, "", "N/A", false, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertTrue(t, strings.Contains(out, "ColorRed"))
+	tst.AssertTrue(t, strings.Contains(out, "package models"))
+}
+
+func TestGenerateEnumSpecsErrorsWithoutPackage(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `// Code generated by enum-generate.go DO NOT EDIT.
+
+package x
+
+type Foo string // @enum:type
+`
+	writeTestFile(t, dir, "z.go", src)
+
+	_, _, _, err := _generateEnumSpecs(dir, "", "N/A", false, false)
+	tst.AssertTrue(t, err != nil)
+}
+
+func TestGenerateEnumSpecsMissingDir(t *testing.T) {
+	dir := filepath.Join(t.TempDir(), "definitely-missing")
+	_, _, _, err := _generateEnumSpecs(dir, "", "N/A", false, false)
+	tst.AssertTrue(t, err != nil)
+}
+
+func TestFmtEnumOutputContainsTypes(t *testing.T) {
+	descr := "the red one"
+	enums := []EnumDef{
+		{
+			File:         "color.go",
+			FileRelative: "color.go",
+			EnumTypeName: "Color",
+			Type:         "string",
+			Values: []EnumDefVal{
+				{VarName: "ColorRed", Value: `"red"`, Description: &descr},
+				{VarName: "ColorBlue", Value: `"blue"`, Description: &descr},
+			},
+		},
+	}
+	out := fmtEnumOutput("CHK1", enums, "models")
+	tst.AssertTrue(t, strings.Contains(out, "package models"))
+	tst.AssertTrue(t, strings.Contains(out, "CHK1"))
+	tst.AssertTrue(t, strings.Contains(out, "ColorRed"))
+	tst.AssertTrue(t, strings.Contains(out, "ColorBlue"))
+	tst.AssertTrue(t, strings.Contains(out, "ParseColor"))
+}
+
+func TestGenerateEnumSpecsSkipsGenFile(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package models
+
+type Color string // @enum:type
+
+const (
+	ColorRed Color = "red"
+)
+`
+	writeTestFile(t, dir, "c.go", src)
+
+	// generated file in same dir - should be filtered out
+	gensrc := `package models
+
+type ShouldBeIgnored string // @enum:type
+`
+	writeTestFile(t, dir, "ignored_gen.go", gensrc)
+
+	out, _, _, err := _generateEnumSpecs(dir, filepath.Join(dir, "enum_gen.go"), "N/A", false, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertTrue(t, strings.Contains(out, "ColorRed"))
+	tst.AssertFalse(t, strings.Contains(out, "ShouldBeIgnored"))
+}
@@ -0,0 +1,209 @@
+package bfcodegen
+
+import (
+	"git.blackforestbytes.com/BlackForestBytes/goext/langext"
+	"git.blackforestbytes.com/BlackForestBytes/goext/tst"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func writeTestFile(t *testing.T, dir string, name string, content string) string {
+	t.Helper()
+	p := filepath.Join(dir, name)
+	err := os.WriteFile(p, []byte(content), 0o644)
+	tst.AssertNoErr(t, err)
+	return p
+}
+
+func TestProcessIDFileSimple(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package mymodels
+
+type UserID string // @id:type
+type OrderID string // @id:type
+`
+	fp := writeTestFile(t, dir, "models.go", src)
+
+	ids, pkg, err := processIDFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, pkg, "mymodels")
+	tst.AssertEqual(t, len(ids), 2)
+	tst.AssertEqual(t, ids[0].Name, "UserID")
+	tst.AssertEqual(t, ids[1].Name, "OrderID")
+	tst.AssertEqual(t, ids[0].FileRelative, "models.go")
+}
+
+func TestProcessIDFileNoMatches(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package x
+
+type Foo string
+type Bar int
+type Baz string // not the right marker
+`
+	fp := writeTestFile(t, dir, "x.go", src)
+
+	ids, pkg, err := processIDFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, pkg, "x")
+	tst.AssertEqual(t, len(ids), 0)
+}
+
+func TestProcessIDFileGeneratedHeaderSkipped(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `// Code generated by id-generate.go DO NOT EDIT.
+
+package x
+
+type SkipMeID string // @id:type
+`
+	fp := writeTestFile(t, dir, "skip.go", src)
+
+	ids, pkg, err := processIDFile(dir, fp, false)
+	tst.AssertNoErr(t, err)
+	tst.AssertEqual(t, pkg, "")
+	tst.AssertEqual(t, len(ids), 0)
+}
+
+func TestProcessIDFileMissingFile(t *testing.T) {
+	_, _, err := processIDFile(t.TempDir(), filepath.Join(t.TempDir(), "does_not_exist.go"), false)
+	tst.AssertTrue(t, err != nil)
+}
+
+func TestGenerateIDSpecsEndToEnd(t *testing.T) {
+	dir := t.TempDir()
+
+	src1 := `package models
+
+type UserID string // @id:type
+type AnyID string // @id:type
+`
+	writeTestFile(t, dir, "a_models.go", src1)
+
+	src2 := `package models
+
+type OrderID string // @id:type
+`
+	writeTestFile(t, dir, "b_models.go", src2)
+
+	dest := filepath.Join(dir, "id_gen.go")
+
+	err := GenerateIDSpecs(dir, dest, IDGenOptions{DebugOutput: langext.PFalse})
+	tst.AssertNoErr(t, err)
+
+	out, err := os.ReadFile(dest)
+	tst.AssertNoErr(t, err)
+	outStr := string(out)
+
+	tst.AssertTrue(t, strings.Contains(outStr, "package models"))
+	tst.AssertTrue(t, strings.Contains(outStr, "ChecksumIDGenerator"))
+	tst.AssertTrue(t, strings.Contains(outStr, "func NewUserID()"))
+	tst.AssertTrue(t, strings.Contains(outStr, "func NewOrderID()"))
+	tst.AssertTrue(t, strings.Contains(outStr, "func NewAnyID()"))
+	tst.AssertTrue(t, strings.Contains(outStr, "AsAny()"))
+}
+
+func TestGenerateIDSpecsIdempotentWhenUnchanged(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package models
+
+type SomeID string // @id:type
+`
+	writeTestFile(t, dir, "models.go", src)
+	dest := filepath.Join(dir, "id_gen.go")
+
+	err := GenerateIDSpecs(dir, dest, IDGenOptions{})
+	tst.AssertNoErr(t, err)
+
+	stat1, err := os.Stat(dest)
+	tst.AssertNoErr(t, err)
+
+	content1, err := os.ReadFile(dest)
+	tst.AssertNoErr(t, err)
+
+	err = GenerateIDSpecs(dir, dest, IDGenOptions{})
+	tst.AssertNoErr(t, err)
+
+	stat2, err := os.Stat(dest)
+	tst.AssertNoErr(t, err)
+
+	content2, err := os.ReadFile(dest)
+	tst.AssertNoErr(t, err)
+
+	tst.AssertEqual(t, stat1.ModTime().Equal(stat2.ModTime()), true)
+	tst.AssertEqual(t, string(content1), string(content2))
+}
+
+func TestGenerateIDSpecsRegeneratesAfterChange(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `package models
+
+type FirstID string // @id:type
+`
+	fp := writeTestFile(t, dir, "models.go", src)
+	dest := filepath.Join(dir, "id_gen.go")
+
+	err := GenerateIDSpecs(dir, dest, IDGenOptions{})
+	tst.AssertNoErr(t, err)
+
+	content1, err := os.ReadFile(dest)
+	tst.AssertNoErr(t, err)
+	tst.AssertTrue(t, strings.Contains(string(content1), "FirstID"))
+	tst.AssertFalse(t, strings.Contains(string(content1), "SecondID"))
+
+	src2 := `package models
+
+type FirstID string // @id:type
+type SecondID string // @id:type
+`
+	err = os.WriteFile(fp, []byte(src2), 0o644)
+	tst.AssertNoErr(t, err)
+
+	err = GenerateIDSpecs(dir, dest, IDGenOptions{})
+	tst.AssertNoErr(t, err)
+
+	content2, err := os.ReadFile(dest)
+	tst.AssertNoErr(t, err)
+	tst.AssertTrue(t, strings.Contains(string(content2), "SecondID"))
+}
+
+func TestGenerateIDSpecsErrorsWithoutPackage(t *testing.T) {
+	dir := t.TempDir()
+
+	src := `// Code generated by id-generate.go DO NOT EDIT.
+
+package x
+
+type SkippedID string // @id:type
+`
+	writeTestFile(t, dir, "z.go", src)
+	dest := filepath.Join(dir, "id_gen.go")
+
+	err := GenerateIDSpecs(dir, dest, IDGenOptions{})
+	tst.AssertTrue(t, err != nil)
+}
+
+func TestGenerateIDSpecsMissingDir(t *testing.T) {
+	dir := filepath.Join(t.TempDir(), "definitely-missing")
+	err := GenerateIDSpecs(dir, filepath.Join(dir, "id_gen.go"), IDGenOptions{})
+	tst.AssertTrue(t, err != nil)
+}
+
+func TestFmtIDOutputContainsAllNames(t *testing.T) {
+	ids := []IDDef{
+		{File: "a.go", FileRelative: "a.go", Name: "AlphaID"},
+		{File: "b.go", FileRelative: "b.go", Name: "BetaID"},
+	}
+	out := fmtIDOutput("CHK_ABC", ids, "models")
+	tst.AssertTrue(t, strings.Contains(out, "package models"))
+	tst.AssertTrue(t, strings.Contains(out, "CHK_ABC"))
+	tst.AssertTrue(t, strings.Contains(out, "AlphaID"))
+	tst.AssertTrue(t, strings.Contains(out, "BetaID"))
+}