Incorrect use of "StrTemplate" (IncorrectUseOfStrTemplate)

Type	Scope	Severity	Activated by default	Minutes to fix	Tags
Error	BSL OS	Blocker	Yes	1	brainoverload suspicious unpredictable

Description

When using the StrTemplate method, you must carefully compose the template string and pass the correct number of parameters. So, it is quite easy to make mistakes when passing values for StrTemplate.

It is important to remember that - StrTemplate only accepts parameters from %1 to %10 - if you want to pass a number immediately after the template, you need to add parentheses - "%(1)45"

Examples

Option 1 - the number of values passed after the template string is not equal (less or more) to the maximum number from a string like %N inside the template string

• StrTemplate("Name (version %1)"); // not passed required parameter for %1
• StrTemplate("%1 (version %2)", Name); // not passed required parameter for %2

Option 2 - no values are passed at all, except for a formatted string due to the large number of parentheses inside a simple expression with NStr and StrTemplate:

• StrTemplate(NStr("en='Name (version %1)'", Version()));

Here mistake not closed parenthesis for NStr. As a result, the expression after evaluating NStr becomes empty. It is rather difficult to detect such an error by reading the code due to the presence of parentheses. And you can only catch it at runtime by getting an exception.

Correct option - StrTemplate(NStr("en='Name (version %1)'"), Version());

Option 3 - correct example of passing digits immediately after a template value - StrTemplate("Name %(1)2"), Name); // if pass the value "MyString", then the result will be "MyString2"

Sources

• Standard: Localization Requirements (RU)

Snippets

Diagnostic ignorance in code

// BSLLS:IncorrectUseOfStrTemplate-off
// BSLLS:IncorrectUseOfStrTemplate-on

Parameter for config

"IncorrectUseOfStrTemplate": false