omzsh-plugin.md
markdown
| 1 | # Oh My ZSH Plugin — Reference |
| 2 | |
| 3 | Minimal, secure ZSH integration for Muse. Provides a prompt segment, core |
| 4 | aliases, and tab completion. Nothing runs automatically beyond what is needed to |
| 5 | keep the prompt accurate. |
| 6 | |
| 7 | --- |
| 8 | |
| 9 | ## Files |
| 10 | |
| 11 | | File | Purpose | |
| 12 | |------|---------| |
| 13 | | `tools/omzsh-plugin/muse.plugin.zsh` | Main plugin (~175 lines) | |
| 14 | | `tools/omzsh-plugin/_muse` | ZSH completion function | |
| 15 | | `tools/install-omzsh-plugin.sh` | Symlink installer | |
| 16 | |
| 17 | --- |
| 18 | |
| 19 | ## Prompt segment |
| 20 | |
| 21 | ```zsh |
| 22 | # In ~/.zshrc |
| 23 | PROMPT='%~ $(muse_prompt_info) %# ' |
| 24 | ``` |
| 25 | |
| 26 | `muse_prompt_info` emits nothing outside a Muse repo. Inside one it emits: |
| 27 | |
| 28 | ``` |
| 29 | %F{magenta}<icon> <branch>%f[ %F{red}✗ <count>%f] |
| 30 | ``` |
| 31 | |
| 32 | The dirty segment (`✗ N`) only appears after a `muse` command has run in the |
| 33 | current shell, because the dirty check requires spawning a subprocess. |
| 34 | |
| 35 | ### Domain icons |
| 36 | |
| 37 | | Domain | Default icon | Config key | |
| 38 | |--------|-------------|-----------| |
| 39 | | `midi` | `♪` | `MUSE_DOMAIN_ICONS[midi]` | |
| 40 | | `code` | `⌥` | `MUSE_DOMAIN_ICONS[code]` | |
| 41 | | `bitcoin` | `₿` | `MUSE_DOMAIN_ICONS[bitcoin]` | |
| 42 | | `scaffold` | `⬡` | `MUSE_DOMAIN_ICONS[scaffold]` | |
| 43 | | (unknown) | `◈` | `MUSE_DOMAIN_ICONS[_default]` | |
| 44 | |
| 45 | --- |
| 46 | |
| 47 | ## Environment variables |
| 48 | |
| 49 | ### Configuration (set before `plugins=(… muse …)`) |
| 50 | |
| 51 | | Variable | Default | Meaning | |
| 52 | |----------|---------|---------| |
| 53 | | `MUSE_PROMPT_ICONS` | `1` | `0` renders `[domain]` instead of icon | |
| 54 | | `MUSE_DIRTY_TIMEOUT` | `1` | Seconds before dirty check aborts | |
| 55 | |
| 56 | ### State (read-only, exported by plugin) |
| 57 | |
| 58 | | Variable | Type | Meaning | |
| 59 | |----------|------|---------| |
| 60 | | `MUSE_REPO_ROOT` | string | Absolute path to repo root, or `""` | |
| 61 | | `MUSE_DOMAIN` | string | Active domain name | |
| 62 | | `MUSE_BRANCH` | string | Branch name, short SHA, or `?` | |
| 63 | | `MUSE_DIRTY` | integer | `1` if working tree has changes | |
| 64 | | `MUSE_DIRTY_COUNT` | integer | Number of changed paths | |
| 65 | |
| 66 | --- |
| 67 | |
| 68 | ## Hooks |
| 69 | |
| 70 | | Hook | When it fires | What it does | |
| 71 | |------|--------------|--------------| |
| 72 | | `chpwd` | On `cd` | Re-finds repo root, re-reads HEAD and domain; clears dirty state | |
| 73 | | `preexec` | Before any command | Sets `_MUSE_CMD_RAN=1` when command is `muse` | |
| 74 | | `precmd` | Before prompt | Runs full refresh (including dirty check) only if `_MUSE_CMD_RAN=1` | |
| 75 | |
| 76 | --- |
| 77 | |
| 78 | ## Aliases |
| 79 | |
| 80 | | Alias | Expands to | |
| 81 | |-------|-----------| |
| 82 | | `mst` | `muse status` | |
| 83 | | `msts` | `muse status --short` | |
| 84 | | `mcm` | `muse commit -m` | |
| 85 | | `mco` | `muse checkout` | |
| 86 | | `mlg` | `muse log` | |
| 87 | | `mlgo` | `muse log --oneline` | |
| 88 | | `mlgg` | `muse log --graph` | |
| 89 | | `mdf` | `muse diff` | |
| 90 | | `mdfst` | `muse diff --stat` | |
| 91 | | `mbr` | `muse branch` | |
| 92 | | `mtg` | `muse tag` | |
| 93 | | `mfh` | `muse fetch` | |
| 94 | | `mpull` | `muse pull` | |
| 95 | | `mpush` | `muse push` | |
| 96 | | `mrm` | `muse remote` | |
| 97 | |
| 98 | --- |
| 99 | |
| 100 | ## Completion |
| 101 | |
| 102 | The `_muse` completion function handles: |
| 103 | |
| 104 | - Top-level command names with descriptions. |
| 105 | - Branch names for `checkout`, `merge`, `cherry-pick`, `branch`, `reset`, `revert`, `diff`, `show`, `blame`. |
| 106 | - Remote names for `push`, `pull`, `fetch`. |
| 107 | - Tag names for `tag`. |
| 108 | - Config key suggestions for `config`. |
| 109 | - Subcommand names for `stash`, `remote`, `plumbing`, `commit` flags. |
| 110 | |
| 111 | All branch/tag/remote lookups use ZSH glob patterns against `.muse/refs/` and |
| 112 | `.muse/remotes/` — no subprocess, no `ls`, instant. |
| 113 | |
| 114 | --- |
| 115 | |
| 116 | ## Performance model |
| 117 | |
| 118 | | Trigger | Subprocesses | What runs | |
| 119 | |---------|-------------|-----------| |
| 120 | | Prompt render | 0 | Reads cached shell vars only | |
| 121 | | `cd` into repo | 1 (`python3`) | HEAD (ZSH read) + domain (python3) | |
| 122 | | `cd` outside repo | 0 | Clears vars only | |
| 123 | | After `muse` command | 1 (`muse status`) | Full refresh + dirty check | |
| 124 | | Tab completion | 0 | ZSH glob reads `.muse/refs/` | |
| 125 | |
| 126 | --- |
| 127 | |
| 128 | ## Security model |
| 129 | |
| 130 | ### Branch name injection |
| 131 | |
| 132 | `.muse/HEAD` is read with a pure ZSH `$(<file)` — no subprocess. Muse writes |
| 133 | the symbolic ref as `refs/heads/<branch>` (no `ref:` prefix). The result is |
| 134 | validated with `[[ "$branch" =~ '^[[:alnum:]/_.-]+$' ]]`. Any branch name that |
| 135 | contains characters outside this set (including `%`, `$`, backticks, quotes) is |
| 136 | replaced with `?`. Valid branch names are additionally `%`-escaped |
| 137 | (`${branch//\%/%%}`) before insertion into the prompt string, so ZSH never |
| 138 | interprets them as prompt directives. |
| 139 | |
| 140 | ### Domain injection |
| 141 | |
| 142 | The domain value from `.muse/repo.json` is extracted by `python3` and validated |
| 143 | with `safe.isalnum() and 1 <= len(v) <= 32` before printing. The path to |
| 144 | `repo.json` is passed via the `MUSE_REPO_JSON` environment variable — never |
| 145 | interpolated into a `-c` string — so a path containing single quotes, spaces, |
| 146 | or special characters is handled safely. |
| 147 | |
| 148 | ### Path injection |
| 149 | |
| 150 | `cd -- "$MUSE_REPO_ROOT"` uses `--` so the path cannot be interpreted as a |
| 151 | flag. `timeout -- ...` follows the same pattern. |
| 152 | |
| 153 | ### No `eval` |
| 154 | |
| 155 | No user-supplied data is ever passed to `eval`. The post-hook system from the |
| 156 | original plugin that `eval`-ed `MUSE_POST_*_CMD` variables has been removed. |
| 157 | |
| 158 | ### Completion safety |
| 159 | |
| 160 | The completion function uses ZSH glob expansion (`${refs_dir}/*(N:t)`) instead |
| 161 | of `$(ls ...)` to enumerate branches. This avoids word-splitting on filenames |
| 162 | that contain spaces, and prevents `ls` output from being treated as shell tokens. |
| 163 | |
| 164 | --- |
| 165 | |
| 166 | ## Installation |
| 167 | |
| 168 | ```bash |
| 169 | bash tools/install-omzsh-plugin.sh |
| 170 | ``` |
| 171 | |
| 172 | The script creates a symlink from `~/.oh-my-zsh/custom/plugins/muse/` to |
| 173 | `tools/omzsh-plugin/`. Because it is a symlink, pulling new commits to the Muse |
| 174 | repo automatically updates the plugin. |
| 175 | |
| 176 | Add to `~/.zshrc`: |
| 177 | |
| 178 | ```zsh |
| 179 | plugins=(git muse) |
| 180 | ``` |
| 181 | |
| 182 | Then reload: |
| 183 | |
| 184 | ```zsh |
| 185 | exec zsh |
| 186 | ``` |