test: add unit tests for QUAL005 missing translations linter rule

6 tests covering:
- Complete translations (no violations)
- Missing language detection (nl_NL missing for one element)
- Single-language project (no violations — nothing to compare)
- Non-translatable strings ignored (empty language)
- Three languages with multiple missing translations
- Rule metadata (ID, category, severity)

Also add NewLintContextFromDB() helper to create LintContext from a
raw sql.DB for testing with in-memory SQLite databases.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ako

mdl/linter/context.go

@@ -37,6 +37,15 @@ func NewLintContext(cat *catalog.Catalog) *LintContext {
 	}
 }
 
+// NewLintContextFromDB creates a new LintContext from a raw database connection.
+// Used in tests to provide an in-memory database with test data.
+func NewLintContextFromDB(db *sql.DB) *LintContext {
+	return &LintContext{
+		db:       db,
+		excluded: make(map[string]bool),
+	}
+}
+
 // SetExcludedModules sets the list of modules to exclude from linting.
 func (ctx *LintContext) SetExcludedModules(modules []string) {
 	ctx.excluded = make(map[string]bool)

mdl/linter/rules/missing_translations_test.go

@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package rules
+
+import (
+	"database/sql"
+	"testing"
+
+	"github.com/mendixlabs/mxcli/mdl/linter"
+
+	_ "modernc.org/sqlite"
+)
+
+// setupTranslationsDB creates an in-memory SQLite database with the strings FTS5 table
+// and inserts test data.
+func setupTranslationsDB(t *testing.T, rows [][]string) *sql.DB {
+	t.Helper()
+	db, err := sql.Open("sqlite", ":memory:")
+	if err != nil {
+		t.Fatalf("failed to open in-memory db: %v", err)
+	}
+
+	_, err = db.Exec(`CREATE VIRTUAL TABLE strings USING fts5(
+		QualifiedName, ObjectType, StringValue, StringContext, Language, ModuleName
+	)`)
+	if err != nil {
+		t.Fatalf("failed to create strings table: %v", err)
+	}
+
+	stmt, err := db.Prepare(`INSERT INTO strings (QualifiedName, ObjectType, StringValue, StringContext, Language, ModuleName)
+		VALUES (?, ?, ?, ?, ?, ?)`)
+	if err != nil {
+		t.Fatalf("failed to prepare insert: %v", err)
+	}
+	defer stmt.Close()
+
+	for _, row := range rows {
+		if len(row) != 6 {
+			t.Fatalf("expected 6 columns, got %d", len(row))
+		}
+		_, err := stmt.Exec(row[0], row[1], row[2], row[3], row[4], row[5])
+		if err != nil {
+			t.Fatalf("failed to insert row: %v", err)
+		}
+	}
+
+	return db
+}
+
+func TestMissingTranslations_NoViolationsWhenComplete(t *testing.T) {
+	db := setupTranslationsDB(t, [][]string{
+		{"MyModule.HomePage", "PAGE", "Welcome", "page_title", "en_US", "MyModule"},
+		{"MyModule.HomePage", "PAGE", "Welkom", "page_title", "nl_NL", "MyModule"},
+	})
+	defer db.Close()
+
+	ctx := linter.NewLintContextFromDB(db)
+	rule := NewMissingTranslationsRule()
+	violations := rule.Check(ctx)
+
+	if len(violations) != 0 {
+		t.Errorf("expected 0 violations, got %d: %v", len(violations), violations)
+	}
+}
+
+func TestMissingTranslations_DetectsMissingLanguage(t *testing.T) {
+	db := setupTranslationsDB(t, [][]string{
+		{"MyModule.HomePage", "PAGE", "Welcome", "page_title", "en_US", "MyModule"},
+		{"MyModule.HomePage", "PAGE", "Welkom", "page_title", "nl_NL", "MyModule"},
+		{"MyModule.EditCustomer", "PAGE", "Edit Customer", "page_title", "en_US", "MyModule"},
+		// nl_NL translation missing for EditCustomer
+	})
+	defer db.Close()
+
+	ctx := linter.NewLintContextFromDB(db)
+	rule := NewMissingTranslationsRule()
+	violations := rule.Check(ctx)
+
+	if len(violations) != 1 {
+		t.Fatalf("expected 1 violation, got %d: %v", len(violations), violations)
+	}
+
+	v := violations[0]
+	if v.RuleID != "QUAL005" {
+		t.Errorf("expected rule ID QUAL005, got %s", v.RuleID)
+	}
+	if v.Location.DocumentName != "MyModule.EditCustomer" {
+		t.Errorf("expected document MyModule.EditCustomer, got %s", v.Location.DocumentName)
+	}
+}
+
+func TestMissingTranslations_SingleLanguageNoViolations(t *testing.T) {
+	// Only one language in the project — nothing to compare
+	db := setupTranslationsDB(t, [][]string{
+		{"MyModule.HomePage", "PAGE", "Welcome", "page_title", "en_US", "MyModule"},
+		{"MyModule.EditCustomer", "PAGE", "Edit Customer", "page_title", "en_US", "MyModule"},
+	})
+	defer db.Close()
+
+	ctx := linter.NewLintContextFromDB(db)
+	rule := NewMissingTranslationsRule()
+	violations := rule.Check(ctx)
+
+	if len(violations) != 0 {
+		t.Errorf("expected 0 violations for single-language project, got %d", len(violations))
+	}
+}
+
+func TestMissingTranslations_NonTranslatableStringsIgnored(t *testing.T) {
+	// Non-translatable strings (empty language) should not trigger violations
+	db := setupTranslationsDB(t, [][]string{
+		{"MyModule.HomePage", "PAGE", "Welcome", "page_title", "en_US", "MyModule"},
+		{"MyModule.HomePage", "PAGE", "Welkom", "page_title", "nl_NL", "MyModule"},
+		{"MyModule.HomePage", "PAGE", "/home", "page_url", "", "MyModule"},
+		{"MyModule.ACT_Process", "MICROFLOW", "Processing items", "documentation", "", "MyModule"},
+	})
+	defer db.Close()
+
+	ctx := linter.NewLintContextFromDB(db)
+	rule := NewMissingTranslationsRule()
+	violations := rule.Check(ctx)
+
+	if len(violations) != 0 {
+		t.Errorf("expected 0 violations, got %d: %v", len(violations), violations)
+	}
+}
+
+func TestMissingTranslations_ThreeLanguages(t *testing.T) {
+	db := setupTranslationsDB(t, [][]string{
+		{"MyModule.HomePage", "PAGE", "Welcome", "page_title", "en_US", "MyModule"},
+		{"MyModule.HomePage", "PAGE", "Welkom", "page_title", "nl_NL", "MyModule"},
+		{"MyModule.HomePage", "PAGE", "Bienvenue", "page_title", "fr_FR", "MyModule"},
+		// EditCustomer only has en_US — missing nl_NL and fr_FR
+		{"MyModule.EditCustomer", "PAGE", "Edit Customer", "page_title", "en_US", "MyModule"},
+	})
+	defer db.Close()
+
+	ctx := linter.NewLintContextFromDB(db)
+	rule := NewMissingTranslationsRule()
+	violations := rule.Check(ctx)
+
+	if len(violations) != 2 {
+		t.Errorf("expected 2 violations (nl_NL + fr_FR missing), got %d: %v", len(violations), violations)
+	}
+}
+
+func TestMissingTranslationsRuleMetadata(t *testing.T) {
+	rule := NewMissingTranslationsRule()
+
+	if rule.ID() != "QUAL005" {
+		t.Errorf("expected ID QUAL005, got %s", rule.ID())
+	}
+	if rule.Category() != "quality" {
+		t.Errorf("expected category 'quality', got %s", rule.Category())
+	}
+	if rule.DefaultSeverity() != linter.SeverityWarning {
+		t.Errorf("expected severity Warning, got %v", rule.DefaultSeverity())
+	}
+}