[Improvement]: Improve bal run to use existing executable when no changes are detected

[Dilhasha]

Description

Currently, the bal run command rebuilds the executable for every execution, even when there are no changes in the source code. This behavior applies to consecutive executions of both bal build and bal run. To avoid rebuilding, users are required to manually provide the executable JAR path, as follows.

bal run <executable-jar-path>  

Describe your problem(s)

This default behavior leads to unnecessary rebuilds, which impacts the execution time and performance, especially for use cases where,

• The same program needs to be run multiple times with different arguments.
• Iterative testing or debugging is being performed without any changes to the source code.

Describe your solution(s)

Update the default behavior of bal run to,

1. Detect whether the source code has been modified since the last build.
2. If no changes are detected, use the existing executable from the previous build instead of rebuilding.

Benefits

• Improved Performance: Eliminates unnecessary rebuilds, reducing execution time.
• Better User Experience: Simplifies execution flows by removing the need for users to provide the executable path manually for reuse
• Efficiency: Enhances the usability of bal run for scenarios that involve multiple executions with unchanged code.

Related area

-> Other Area

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