Issue #29: Go refactor errors

[icahoon]

Issue

Fixes #29

Summary

Adds an ErrorCode struct which provides a return code to os.Exit in Main.
Four manifest errors values have been defined

• ErrUsage: for usage errors that can be corrected by the user
• ErrIntenal: an internal error that is beyond the control of the user
• ErrUnimplemented: an unimplemented feature
• ErrUnknown: an unknown error has occurred

The entropylex command has been refactored to use these errors.

Key Changes

• The OutputFile and InputFile functions have been moved to their on files, outputfile.go and inputfile.go. The accompanying unit tests have also been moved to outputfile_test.go and inputfile_test.go.
• now using go1.27
• enhances the "clean" make target

Design Rationale

The errors are properly isolated to the entropylex command, since they convey return result only relevant to the cli command.

Test Plan

• updated unit tests where necessary
• adds new unit test for ErrorCode

[icahoon]

Code review — PR #30 (feat/issue-29-go-refactor-errors)

High-effort review of the diff vs main. Six findings, most severe first.

🔴 Blocking / correctness

1. Test imports a bare uuid package that only exists locally — entropylex/cmd/entropylex/outputfile_test.go:7
The test imports "uuid", which resolves to a manually-added /usr/local/go/src/uuid. go.mod dropped github.com/google/uu id, so on any clean toolchain (CI included) the package won't compile — package uuid is not in std — and the whole package' s tests fail before running. Restore github.com/google/uuid.NewString().

2. Invalid -b now truncates the output file (data loss) — entropylex/cmd/entropylex/command.go:95
Deleting the bit-depth flag Validator moved validation into the Action, which runs OutputFile() (create/truncate) before rejecting a bad -b. So entropylex -b 42 -o existing.dat --force truncates existing.dat to 0 bytes, then errors. Previou sly the flag validator rejected it at parse time, before any file was touched.

3. make clean wipes the shared module cache — Makefile:149
go clean -i -r -cache -testcache -modcache -fuzzcache — the -modcache blows away $GOMODCACHE for every Go project on t he machine, forcing a full re-download next build. -i -r also removes installed archives for all deps recursively.

🟡 Consistency / coverage

4. %s instead of %w breaks the error chain — entropylex/cmd/entropylex/command.go:97
fmt.Errorf("%w: %s", ErrUsage, err) on the OutputFile path drops err from the unwrap chain, while the adjacent InputFile p ath (command.go:113) correctly uses %w: %w. Two otherwise-identical paths behave differently under errors.Is/As.

5. Usage errors no longer print command help — entropylex/cmd/entropylex/command.go:96
Removing DefaultShowRootCommandHelp means a usage error now prints only the one-line message from main.go, no usage guidan ce. Possibly intentional (tests were updated) — worth confirming the UX is intended.

6. Test_NewEntropyLex8 is an empty // TODO that always passes — entropylex/cmd/entropylex/entropylex8_test.go:8
The three new ErrInternal-wrapping branches added to NewEntropyLex8 in this PR are untested; the placeholder reports succe ss without exercising any of them.

_{🤖 Generated with Claude Code}

[icahoon]

Code review — PR #30 (feat/issue-29-go-refactor-errors)

High-effort review of the diff vs main. Six findings, most severe first.

🔴 Blocking / correctness

1. Test imports a bare uuid package that only exists locally — entropylex/cmd/entropylex/outputfile_test.go:7 The test imports "uuid", which resolves to a manually-added /usr/local/go/src/uuid. go.mod dropped github.com/google/uu id, so on any clean toolchain (CI included) the package won't compile — package uuid is not in std — and the whole package' s tests fail before running. Restore github.com/google/uuid.NewString().

This is incorrect. go1.27 now includes a uuid package.

2. Invalid -b now truncates the output file (data loss) — entropylex/cmd/entropylex/command.go:95 Deleting the bit-depth flag Validator moved validation into the Action, which runs OutputFile() (create/truncate) before rejecting a bad -b. So entropylex -b 42 -o existing.dat --force truncates existing.dat to 0 bytes, then errors. Previou sly the flag validator rejected it at parse time, before any file was touched.

I'll fix this.

3. make clean wipes the shared module cache — Makefile:149 go clean -i -r -cache -testcache -modcache -fuzzcache — the -modcache blows away $GOMODCACHE for every Go project on t he machine, forcing a full re-download next build. -i -r also removes installed archives for all deps recursively.

I'm fine withe the entire module cache being destroyed.

🟡 Consistency / coverage

4. %s instead of %w breaks the error chain — entropylex/cmd/entropylex/command.go:97 fmt.Errorf("%w: %s", ErrUsage, err) on the OutputFile path drops err from the unwrap chain, while the adjacent InputFile p ath (command.go:113) correctly uses %w: %w. Two otherwise-identical paths behave differently under errors.Is/As.

I'll fix this.

5. Usage errors no longer print command help — entropylex/cmd/entropylex/command.go:96 Removing DefaultShowRootCommandHelp means a usage error now prints only the one-line message from main.go, no usage guidan ce. Possibly intentional (tests were updated) — worth confirming the UX is intended.

This is intended.

6. Test_NewEntropyLex8 is an empty // TODO that always passes — entropylex/cmd/entropylex/entropylex8_test.go:8 The three new ErrInternal-wrapping branches added to NewEntropyLex8 in this PR are untested; the placeholder reports succe ss without exercising any of them.

This is fine for now.

🤖 Generated with Claude Code

[XenonofArcticus]

Within my skill and effort, this looks reasonable.