v1.4.0: Major Skills Expansion - 75 Total Skills

skills/superpowers/tests/subagent-driven-dev/go-fractals/plan.md

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+# Go Fractals CLI - Implementation Plan
+
+Execute this plan using the `superpowers:subagent-driven-development` skill.
+
+## Context
+
+Building a CLI tool that generates ASCII fractals. See `design.md` for full specification.
+
+## Tasks
+
+### Task 1: Project Setup
+
+Create the Go module and directory structure.
+
+**Do:**
+- Initialize `go.mod` with module name `github.com/superpowers-test/fractals`
+- Create directory structure: `cmd/fractals/`, `internal/sierpinski/`, `internal/mandelbrot/`, `internal/cli/`
+- Create minimal `cmd/fractals/main.go` that prints "fractals cli"
+- Add `github.com/spf13/cobra` dependency
+
+**Verify:**
+- `go build ./cmd/fractals` succeeds
+- `./fractals` prints "fractals cli"
+
+---
+
+### Task 2: CLI Framework with Help
+
+Set up Cobra root command with help output.
+
+**Do:**
+- Create `internal/cli/root.go` with root command
+- Configure help text showing available subcommands
+- Wire root command into `main.go`
+
+**Verify:**
+- `./fractals --help` shows usage with "sierpinski" and "mandelbrot" listed as available commands
+- `./fractals` (no args) shows help
+
+---
+
+### Task 3: Sierpinski Algorithm
+
+Implement the Sierpinski triangle generation algorithm.
+
+**Do:**
+- Create `internal/sierpinski/sierpinski.go`
+- Implement `Generate(size, depth int, char rune) []string` that returns lines of the triangle
+- Use recursive midpoint subdivision algorithm
+- Create `internal/sierpinski/sierpinski_test.go` with tests:
+  - Small triangle (size=4, depth=2) matches expected output
+  - Size=1 returns single character
+  - Depth=0 returns filled triangle
+
+**Verify:**
+- `go test ./internal/sierpinski/...` passes
+
+---
+
+### Task 4: Sierpinski CLI Integration
+
+Wire the Sierpinski algorithm to a CLI subcommand.
+
+**Do:**
+- Create `internal/cli/sierpinski.go` with `sierpinski` subcommand
+- Add flags: `--size` (default 32), `--depth` (default 5), `--char` (default '*')
+- Call `sierpinski.Generate()` and print result to stdout
+
+**Verify:**
+- `./fractals sierpinski` outputs a triangle
+- `./fractals sierpinski --size 16 --depth 3` outputs smaller triangle
+- `./fractals sierpinski --help` shows flag documentation
+
+---
+
+### Task 5: Mandelbrot Algorithm
+
+Implement the Mandelbrot set ASCII renderer.
+
+**Do:**
+- Create `internal/mandelbrot/mandelbrot.go`
+- Implement `Render(width, height, maxIter int, char string) []string`
+- Map complex plane region (-2.5 to 1.0 real, -1.0 to 1.0 imaginary) to output dimensions
+- Map iteration count to character gradient " .:-=+*#%@" (or single char if provided)
+- Create `internal/mandelbrot/mandelbrot_test.go` with tests:
+  - Output dimensions match requested width/height
+  - Known point inside set (0,0) maps to max-iteration character
+  - Known point outside set (2,0) maps to low-iteration character
+
+**Verify:**
+- `go test ./internal/mandelbrot/...` passes
+
+---
+
+### Task 6: Mandelbrot CLI Integration
+
+Wire the Mandelbrot algorithm to a CLI subcommand.
+
+**Do:**
+- Create `internal/cli/mandelbrot.go` with `mandelbrot` subcommand
+- Add flags: `--width` (default 80), `--height` (default 24), `--iterations` (default 100), `--char` (default "")
+- Call `mandelbrot.Render()` and print result to stdout
+
+**Verify:**
+- `./fractals mandelbrot` outputs recognizable Mandelbrot set
+- `./fractals mandelbrot --width 40 --height 12` outputs smaller version
+- `./fractals mandelbrot --help` shows flag documentation
+
+---
+
+### Task 7: Character Set Configuration
+
+Ensure `--char` flag works consistently across both commands.
+
+**Do:**
+- Verify Sierpinski `--char` flag passes character to algorithm
+- For Mandelbrot, `--char` should use single character instead of gradient
+- Add tests for custom character output
+
+**Verify:**
+- `./fractals sierpinski --char '#'` uses '#' character
+- `./fractals mandelbrot --char '.'` uses '.' for all filled points
+- Tests pass
+
+---
+
+### Task 8: Input Validation and Error Handling
+
+Add validation for invalid inputs.
+
+**Do:**
+- Sierpinski: size must be > 0, depth must be >= 0
+- Mandelbrot: width/height must be > 0, iterations must be > 0
+- Return clear error messages for invalid inputs
+- Add tests for error cases
+
+**Verify:**
+- `./fractals sierpinski --size 0` prints error, exits non-zero
+- `./fractals mandelbrot --width -1` prints error, exits non-zero
+- Error messages are clear and helpful
+
+---
+
+### Task 9: Integration Tests
+
+Add integration tests that invoke the CLI.
+
+**Do:**
+- Create `cmd/fractals/main_test.go` or `test/integration_test.go`
+- Test full CLI invocation for both commands
+- Verify output format and exit codes
+- Test error cases return non-zero exit
+
+**Verify:**
+- `go test ./...` passes all tests including integration tests
+
+---
+
+### Task 10: README
+
+Document usage and examples.
+
+**Do:**
+- Create `README.md` with:
+  - Project description
+  - Installation: `go install ./cmd/fractals`
+  - Usage examples for both commands
+  - Example output (small samples)
+
+**Verify:**
+- README accurately describes the tool
+- Examples in README actually work