Merge pull request #295 from zoncoen/template

fix(template): evaluate only an expression that matched the condition

template/template.go

@@ -437,18 +437,10 @@ func (t *Template) executeConditionalExpr(e *ast.ConditionalExpr, data interface
 	if !ok {
 		return nil, fmt.Errorf("invalid operation: operator ? not defined on %#v (value of type %T)", c, c)
 	}
-	x, err := t.executeExpr(e.X, data)
-	if err != nil {
-		return nil, err
-	}
-	y, err := t.executeExpr(e.Y, data)
-	if err != nil {
-		return nil, err
-	}
 	if condition {
-		return x, nil
+		return t.executeExpr(e.X, data)
 	}
-	return y, nil
+	return t.executeExpr(e.Y, data)
 }
 
 // align indents of marshaled texts

template/template_test.go

@@ -1036,9 +1036,18 @@ func TestTemplate_Execute_BinaryExpr(t *testing.T) {
 				str:         `{{1 ? 1 : 2}}`,
 				expectError: `failed to execute: {{1 ? 1 : 2}}: invalid operation: operator ? not defined on 1 (value of type int64)`,
 			},
-			"true ? 1 : 2 + true": {
-				str:         `{{true ? 1 : 2 + true}}`,
-				expectError: `failed to execute: {{true ? 1 : 2 + true}}: invalid operation: 2 + true: mismatched types int64 and bool`,
+			`defined(v) ? v : "default" + true`: {
+				// "default" + true should not be evaluated
+				str: `{{defined(v) ? v : "default" + true}}`,
+				data: map[string]interface{}{
+					"v": "override",
+				},
+				expect: "override",
+			},
+			`defined(v) ? v + true : "default"`: {
+				// v + true should not be evaluated
+				str:    `{{defined(v) ? v : "default"}}`,
+				expect: "default",
 			},
 		}
 		runExecute(t, tests)