Replace expressions engine (#133)

internal/templateeval/rewrite_subexpression_test.go

@@ -0,0 +1,115 @@
+package templateeval
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRewriteSubExpression_NoExpression(t *testing.T) {
+	in := "Hello world"
+	out, ok, err := rewriteSubExpression(in, false)
+	assert.NoError(t, err)
+	if ok {
+		t.Fatalf("expected ok=false for no expression, got true with output %q", out)
+	}
+	if out != in {
+		t.Fatalf("expected output %q, got %q", in, out)
+	}
+}
+
+func TestRewriteSubExpression_SingleExpression(t *testing.T) {
+	in := "Hello ${{ 'world' }}"
+	out, ok, err := rewriteSubExpression(in, false)
+	assert.NoError(t, err)
+	if !ok {
+		t.Fatalf("expected ok=true for single expression, got false")
+	}
+	expected := "format('Hello {0}', 'world')"
+	if out != expected {
+		t.Fatalf("expected %q, got %q", expected, out)
+	}
+}
+
+func TestRewriteSubExpression_MultipleExpressions(t *testing.T) {
+	in := "Hello ${{ 'world' }}, you are ${{ 'awesome' }}"
+	out, ok, err := rewriteSubExpression(in, false)
+	assert.NoError(t, err)
+	if !ok {
+		t.Fatalf("expected ok=true for multiple expressions, got false")
+	}
+	expected := "format('Hello {0}, you are {1}', 'world', 'awesome')"
+	if out != expected {
+		t.Fatalf("expected %q, got %q", expected, out)
+	}
+}
+
+func TestRewriteSubExpression_ForceFormatSingle(t *testing.T) {
+	in := "Hello ${{ 'world' }}"
+	out, ok, err := rewriteSubExpression(in, true)
+	assert.NoError(t, err)
+	if !ok {
+		t.Fatalf("expected ok=true when forceFormat, got false")
+	}
+	expected := "format('Hello {0}', 'world')"
+	if out != expected {
+		t.Fatalf("expected %q, got %q", expected, out)
+	}
+}
+
+func TestRewriteSubExpression_ForceFormatMultiple(t *testing.T) {
+	in := "Hello ${{ 'world' }}, you are ${{ 'awesome' }}"
+	out, ok, err := rewriteSubExpression(in, true)
+	assert.NoError(t, err)
+	if !ok {
+		t.Fatalf("expected ok=true when forceFormat, got false")
+	}
+	expected := "format('Hello {0}, you are {1}', 'world', 'awesome')"
+	if out != expected {
+		t.Fatalf("expected %q, got %q", expected, out)
+	}
+}
+
+func TestRewriteSubExpression_UnclosedExpression(t *testing.T) {
+	in := "Hello ${{ 'world' " // missing closing }}
+	_, _, err := rewriteSubExpression(in, false)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "unclosed expression")
+}
+
+func TestRewriteSubExpression_UnclosedString(t *testing.T) {
+	in := "Hello ${{ 'world }}, you are ${{ 'awesome' }}"
+	_, _, err := rewriteSubExpression(in, false)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "unclosed string")
+}
+
+func TestRewriteSubExpression_EscapedStringLiteral(t *testing.T) {
+	// Two single quotes represent an escaped quote inside a string
+	in := "Hello ${{ 'It''s a test' }}"
+	out, ok, err := rewriteSubExpression(in, false)
+	assert.NoError(t, err)
+	assert.True(t, ok)
+	expected := "format('Hello {0}', 'It''s a test')"
+	assert.Equal(t, expected, out)
+}
+
+func TestRewriteSubExpression_ExpressionAtEnd(t *testing.T) {
+	// Expression ends exactly at the string end – should be valid
+	in := "Hello ${{ 'world' }}"
+	out, ok, err := rewriteSubExpression(in, false)
+	assert.NoError(t, err)
+	assert.True(t, ok)
+	expected := "format('Hello {0}', 'world')"
+	assert.Equal(t, expected, out)
+}
+
+func TestRewriteSubExpression_ExpressionNotAtEnd(t *testing.T) {
+	// Expression followed by additional text – should still be valid
+	in := "Hello ${{ 'world' }}, how are you?"
+	out, ok, err := rewriteSubExpression(in, false)
+	assert.NoError(t, err)
+	assert.True(t, ok)
+	expected := "format('Hello {0}, how are you?', 'world')"
+	assert.Equal(t, expected, out)
+}