Merge pull request #32 from John-Goff/git-prompt

Add prompt which displays short working directory and git status of current directory

README.md

@@ -33,5 +33,6 @@ You can run nushell scripts in a few different ways.
 | not assigned yet | [progress_bar.nu](./progress_bar.nu)                      | 0.26       | Draws a progress bar        |
 | not assigned yet | [progress_bar_no_back.nu](./progress_bar_no_back.nu)      | 0.26       | Draws a progress bar with no background        |
 | prompt           | [myprompt.nu](./prompt/myprompt.nu)                       | 0.26       | Prototype script to create a prompt.        |
+| prompt           | [git_status_prompt.nu](./prompt/git_status_prompt.nu)     | 0.28       | Creates a prompt which includes short working directory and current git status.        |
 | stdlib_candidate | [nu_style.nu](./stdlib_candidate/nu_style.nu)             | 0.26       | Define colors as names.        |
 | stdlib_candidate | [print.nu](./stdlib_candidate/print.nu)                   | 0.26       | Examples of a print statement.        |

prompt/git_status_prompt.nu

@@ -0,0 +1,94 @@
+# Displays a prompt
+def git-status-prompt [] {
+  build-string $(ansi reset) $(ansi green) $(whoami | str trim) $(ansi reset) @ $(hostname -s | str trim) : $(ansi green_dimmed) $(prompt-pwd) $(ansi reset) $(git-branch-icon) $(ansi reset) $(char newline) '➤ '
+}
+
+# Returns a shortened pwd for use in prompt
+def prompt-pwd [] {
+  let path = $(pwd | split row "/")
+  let home = $(echo $nu.env.HOME | split row "/")
+
+  if $(echo $path | count) > 1 {
+    if $(echo $home | reduce { = $it in $path }) {
+      let path-without-home = $(echo $path | skip $(echo $home | count))
+
+      if $(echo $path-without-home | wrap | compact | count) > 0 {
+        let parent = $(echo $path | skip $(echo $home | count) | drop)
+
+        if $(echo $parent | wrap | compact | count) > 0 {
+          let short-part = $(echo $parent | each {
+            if $(echo $it | str starts-with ".") {
+              echo $(echo $it | str substring [0 2]) "/"
+            } {
+              echo $(echo $it | str substring [0 1]) "/"
+            }
+          })
+          echo "~/" $short-part $(echo $path | last) | str collect
+        } {
+          echo "~/" $(echo $path | last) | str collect
+        }
+      } {
+        echo "~"
+      }
+    } {
+      let parent = $(echo $path | drop | str substring [0 1] | each { echo $it "/" })
+      echo "/" $parent $(echo $path | last) | str collect
+    }
+  } {
+    pwd
+  }
+}
+
+# Map of git status codes to ANSI colour codes
+def git-prompt-map [] {
+  echo a m r c d "??" u |
+  rotate counter-clockwise |
+  reject Column0 | append $(
+    echo $(ansi green) $(ansi yellow_bold) $(ansi cyan) $(ansi blue) $(ansi red) $(ansi red_dimmed) $(ansi red) |
+    rotate counter-clockwise |
+    reject Column0
+  ) | headers
+}
+
+# Gets an icon and a colour for a given git status code
+def git-prompt-icons [k] {
+  let icns = ["✚ " "* " "➜ " "⇒ " "✖ " "? " "! "];
+
+  git-prompt-map |
+  pivot status colour | each --numbered {
+    let idx = $it.index;
+
+    if $it.item.status == $k {
+      build-string $it.item.colour $(echo $icns | nth $idx)
+    } {
+      = $nothing
+    }
+  } | compact
+}
+
+# Checks git status of current working directory and displays an icon
+def git-branch-icon [] {
+  do -i {
+    let branch = $(do -i { git rev-parse --abbrev-ref HEAD } | str trim)
+    
+    if $(echo $branch | str length) > 0 {
+      let modified = $(do -i { git status --porcelain } | split row "\n" | str trim | split column " " status file);
+
+      if $(echo $modified | get | first | empty?) {
+        build-string "|" $(ansi green) $branch $(ansi reset) ":" $(ansi green) '✓' $(ansi reset)
+      } {
+        let modified2 = $(do -i { git status --porcelain } | split row "\n" | str substring [0 1])
+        let branch-colour = $(if $(echo $modified2 | each { = $it in [A M R C D] } | reduce { = $it || $acc }) {
+          echo yellow
+        } {
+          echo red
+        })
+        build-string "|" $(ansi $branch-colour) $branch $(ansi reset) ":" $(echo $modified | get status | uniq | str downcase | each {
+          git-prompt-icons $it
+        } | str collect)
+      }
+    } {
+      echo ""
+    }
+  }
+}