Introduce Workbook#[] and implement Enumerable

README.md

@@ -45,9 +45,12 @@ Xsv has two modes of operation. By default, it returns an array for
 each row in the sheet:
 
 ```ruby
-x = Xsv.open("sheet.xlsx") # => #<Xsv::Workbook sheets=1>
+workbook = Xsv.open("sheet.xlsx") # => #<Xsv::Workbook sheets=1>
 
-sheet = x.sheets[0]
+# Access worksheet by index, 0 is the first sheet
+sheet = workbook[0]
+# or, access worksheet by name
+sheet = workbook["Sheet1"]
 
 # Iterate over rows
 sheet.each do |row|
@@ -65,15 +68,16 @@ option on open:
 ```ruby
 # Parse headers for all sheets on open
 
-x = Xsv.open("sheet.xlsx", parse_headers: true)
+workbook = Xsv.open("sheet.xlsx", parse_headers: true)
 
-x.sheets[0][1]   # => {"header1" => "value1", "header2" => "value2"}
+# Get the first row from the first sheet
+workbook.first.first   # => {"header1" => "value1", "header2" => "value2"}
 
 # Manually parse headers for a single sheet
 
-x = Xsv.open("sheet.xlsx")
+workbook = Xsv.open("sheet.xlsx")
 
-sheet = x.sheets[0]
+sheet = workbook[0]
 
 sheet[0]  # => ["header1", "header2"]
 
@@ -86,7 +90,13 @@ Xsv will raise `Xsv::DuplicateHeaders` if it detects duplicate values in the hea
 `#parse_headers!` or when opening a workbook with `parse_headers: true` to ensure hash keys are unique.
 
 `Xsv::Sheet` implements `Enumerable` so along with `#each`
-you can call methods like `#first`, `#filter`/`#select`, and `#map` on it.
+you can call methods like `#first`, `#filter`/`#select`, and `#map` on it. Likewise these methods can
+be used on `Xsv::Workbook` to iterate over sheets, for example:
+
+```ruby
+# Get the name of all the sheets in a workbook
+sheet_names = @workbook.map(&:name)
+```
 
 ### Opening a string or buffer instead of filename
 
@@ -112,24 +122,6 @@ end
 Prior to Xsv 1.1.0, `Xsv::Workbook.open` was used instead of `Xsv.open`. The parameters are identical and
 the former is maintained for backwards compatibility.
 
-### Accessing sheets by name
-
-The sheets can be accessed by index or by name:
-
-```ruby
-x = Xsv.open("sheet.xlsx")
-
-sheet = x.sheets[0] # gets sheet by index
-
-sheet = x.sheets_by_name('Name').first # gets sheet by name
-```
-
-To get all the sheets names:
-
-```ruby
-sheet_names = x.sheets.map(&:name)
-```
-
 ### Assumptions
 
 Since Xsv treats worksheets like csv files it makes certain assumptions about your

lib/xsv/workbook.rb

@@ -6,6 +6,8 @@ module Xsv
   # An OOXML Spreadsheet document is called a Workbook. A Workbook consists of
   # multiple Sheets that are available in the array that's accessible through {#sheets}
   class Workbook
+    include Enumerable
+
     # Access the Sheet objects contained in the workbook
     # @return [Array<Sheet>]
     attr_reader :sheets
@@ -69,6 +71,24 @@ def get_num_fmt(style)
       @num_fmts[@xfs[style][:numFmtId]]
     end
 
+    def each(&block)
+      sheets.each(&block)
+    end
+
+    # Get a sheet by index or name
+    # @param [String, Integer] index_or_name The name of the sheet or index in the workbook
+    # @return [<Xsv::Sheet>, nil] returns the sheet instance or nil if it was not found
+    def [](index_or_name)
+      case index_or_name
+      when Integer
+        sheets[index_or_name]
+      when String
+        sheets_by_name(index_or_name).first
+      else
+        raise ArgumentError, "Sheets can be accessed by Integer of String only"
+      end
+    end
+
     private
 
     def fetch_shared_strings

test/workbook_test.rb

@@ -112,4 +112,52 @@ def test_open_xml_sdk
     assert_equal "2022-03-04 12:00:00 AM", @sheet[0]["Date"]
     assert_equal "ABC123", @sheet[0]["Value"]
   end
+
+  def test_index_open_by_index
+    @workbook = Xsv.open(File.read("test/files/office365-xl7.xlsx"))
+
+    sheet = @workbook[1]
+    assert_equal "Blad2", sheet.name
+  end
+
+  def test_index_open_by_out_of_range_index
+    @workbook = Xsv.open(File.read("test/files/office365-xl7.xlsx"))
+
+    sheet = @workbook[99]
+    assert_nil sheet
+  end
+
+  def test_index_open_by_name
+    @workbook = Xsv.open(File.read("test/files/office365-xl7.xlsx"))
+
+    sheet = @workbook["Blad2"]
+    assert_equal "Blad2", sheet.name
+  end
+
+  def test_index_open_by_nonexistent_name
+    @workbook = Xsv.open(File.read("test/files/office365-xl7.xlsx"))
+
+    sheet = @workbook["Blad99"]
+    assert_nil sheet
+  end
+
+  def test_index_open_by_invalid_type
+    @workbook = Xsv.open(File.read("test/files/office365-xl7.xlsx"))
+
+    assert_raises ArgumentError do
+      @workbook[true]
+    end
+  end
+
+  def test_first
+    @workbook = Xsv.open(File.read("test/files/office365-xl7.xlsx"))
+
+    assert_equal "Blad1", @workbook.first.name
+  end
+
+  def test_enumerable
+    @workbook = Xsv.open(File.read("test/files/office365-xl7.xlsx"))
+
+    assert_equal %w(Blad1 Blad2 Blad3), @workbook.map(&:name)
+  end
 end