Summary

The --showConfig flag was incorrectly failing when no input files matched the include patterns, even though its purpose is to display the parsed configuration without compilation. This change allows --showConfig to work properly regardless of whether input files are present.

Problem

Previously, running tsc --showConfig with a configuration like:

{"include": ["./*"]}

...in an empty directory would fail with:

error TS18003: No inputs were found in config file 'tsconfig.json'. Specified 'include' paths were '["./*"]' and 'exclude' paths were '[]'.

Solution

Modified executeCommandLine.ts to filter out "No inputs were found" errors (TS18003) when the --showConfig flag is used, since the purpose is to show configuration, not to compile files.

Behavior

Before:

$ tsc --showConfig  # in empty directory
error TS18003: No inputs were found in config file...

After:

$ tsc --showConfig  # in empty directory
{
    "compilerOptions": {},
    "include": [
        "./*"
    ]
}

Other errors (like invalid compiler options) are still properly reported when using --showConfig.

Testing

• Added integration tests covering the fix
• Verified that other errors are still reported correctly
• Ran the full test suite with 93,609+ tests passing

Fixes #48443.

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