feat: text alignment (#16)

* enhancement(formatting): provide text alignment for table cells

- Add `alignment` parameter to `cell` function to control text alignment to be left, right, or center.

* enhancement(formatting): provide cell-level text alignment for tables

Add `alignment` field to `format_opts` type to configure alignment passed to formatter code.

* enhancement(formatting): provide cell-level text alignment for tables

For `:center` alignment, add back possible lost space due to integer division.

lib/formatter.ex

@@ -37,8 +37,13 @@ defmodule Scribe.Formatter.Line do
 
         cell_value =
           case opts[:colorize] do
-            false -> value |> cell(width)
-            _ -> value |> cell(width) |> colorize(style.color(value))
+            false ->
+              value |> cell(width, opts[:alignment])
+
+            _ ->
+              value
+              |> cell(width, opts[:alignment])
+              |> colorize(style.color(value))
           end
 
         acc <> cell_value <> b.right_edge
@@ -47,10 +52,25 @@ defmodule Scribe.Formatter.Line do
     left_edge <> line <> "\n"
   end
 
-  def cell(x, width) do
+  def cell(x, width, alignment \\ :left) do
     len = min(String.length(" #{inspect(x)} "), width)
-    padding = String.duplicate(" ", width - len)
-    truncate(" #{inspect(x)}#{padding}", width - 2) <> " "
+
+    case alignment do
+      :center ->
+        padding = String.duplicate(" ", div(width - len, 2))
+        remaining = String.duplicate(" ", rem(width - len, 2))
+
+        truncate(" #{padding}#{inspect(x)}#{padding}#{remaining}", width - 2) <>
+          " "
+
+      :right ->
+        padding = String.duplicate(" ", width - len)
+        truncate(" #{padding}#{inspect(x)}", width - 2) <> " "
+
+      _ ->
+        padding = String.duplicate(" ", width - len)
+        truncate(" #{inspect(x)}#{padding}", width - 2) <> " "
+    end
   end
 
   def cell_value(x, padding, max_width) when padding >= 0 do

lib/scribe.ex

@@ -13,13 +13,15 @@ defmodule Scribe do
   @typedoc ~S"""
   Options for configuring table output.
 
+  - `:alignment` - Define text alignment in cells. Defaults to `:left`.
   - `:colorize` - When `false`, disables colored output. Defaults to `true`
   - `:data` - Defines table headers
   - `:device` - Where to print (defaults to STDOUT)
   - `:style` - Style callback module. Defaults to `Scribe.Style.Default`
   - `:width` - Defines table width. Defaults to `:infinite`
   """
   @type format_opts :: [
+          alignment: atom,
           colorize: boolean,
           data: [...],
           style: module,