chore: add unit testcases for files in Text format. (#2274)

* chore: add unit testcases for files in Text format.

Signed-off-by: Electronic-Waste <[email protected]>

* chore: adjust file layout using gofmt.

Signed-off-by: Electronic-Waste <[email protected]>

* chore: combine test for JSON and TEXT file format.

Signed-off-by: Electronic-Waste <[email protected]>

* fix: rename file-gen functions.

Signed-off-by: Electronic-Waste <[email protected]>

* refactor: update cmd.Diff params and log outputs.

Signed-off-by: Electronic-Waste <[email protected]>

* chore: add more valid and invalid testcases for TEXT format.

Signed-off-by: Electronic-Waste <[email protected]>

* chore: convert testcase name to const.

Signed-off-by: Electronic-Waste <[email protected]>

* chore: compact dir generation & deletion operations into funcs.

Signed-off-by: Electronic-Waste <[email protected]>

* fix: delete constants used only once.

Signed-off-by: Electronic-Waste <[email protected]>

* fix: fix ci error in errorcheck.

Signed-off-by: Electronic-Waste <[email protected]>

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Signed-off-by: Electronic-Waste <[email protected]>