move logic to find an executable from ConfigureOp to Util

lib/rscons/configure_op.rb

@@ -184,22 +184,8 @@ module Rscons
     # Check for a executable program.
     def check_program(program, options = {})
       Ansi.write($stdout, "Checking for program '", :cyan, program, :reset, "'... ")
-      found = false
-      if program["/"] or program["\\"]
-        if File.file?(program) and File.executable?(program)
-          found = true
-          success_message = program
-        end
-      else
-        path_entries = ENV["PATH"].split(File::PATH_SEPARATOR)
-        path_entries.find do |path_entry|
-          if path = test_path_for_executable(path_entry, program)
-            found = true
-            success_message = path
-          end
-        end
-      end
-      common_config_checks(found ? 0 : 1, options.merge(success_message: success_message))
+      path = Util.find_executable(program)
+      common_config_checks(path ? 0 : 1, options.merge(success_message: path))
     end
 
     private
@@ -401,34 +387,5 @@ module Rscons
       end
     end
 
-    # Check if a directory contains a certain executable.
-    #
-    # @param path_entry [String]
-    #   Directory to look in.
-    # @param executable [String]
-    #   Executable to look for.
-    def test_path_for_executable(path_entry, executable)
-      is_executable = lambda do |path|
-        File.file?(path) and File.executable?(path)
-      end
-      if RbConfig::CONFIG["host_os"] =~ /mswin|windows|mingw/i
-        executable = executable.downcase
-        dir_entries = Dir.entries(path_entry)
-        dir_entries.find do |entry|
-          path = "#{path_entry}/#{entry}"
-          entry = entry.downcase
-          if ((entry == executable) or
-              (entry == "#{executable}.exe") or
-              (entry == "#{executable}.com") or
-              (entry == "#{executable}.bat")) and is_executable[path]
-            return path
-          end
-        end
-      else
-        path = "#{path_entry}/#{executable}"
-        return path if is_executable[path]
-      end
-    end
-
   end
 end

lib/rscons/util.rb

@@ -34,6 +34,56 @@ module Rscons
         end
       end
 
+      # Look for an executable.
+      #
+      # @return [String, nil]
+      #   Executable path, if found.
+      def find_executable(name)
+        if name["/"] or name["\\"]
+          if File.file?(name) and File.executable?(name)
+            return name
+          end
+        else
+          path_entries = ENV["PATH"].split(File::PATH_SEPARATOR)
+          path_entries.find do |path_entry|
+            if path = test_path_for_executable(path_entry, name)
+              return path
+            end
+          end
+        end
+      end
+
+      private
+
+      # Check if a directory contains a certain executable.
+      #
+      # @param path_entry [String]
+      #   Directory to look in.
+      # @param executable [String]
+      #   Executable to look for.
+      def test_path_for_executable(path_entry, executable)
+        is_executable = lambda do |path|
+          File.file?(path) and File.executable?(path)
+        end
+        if RbConfig::CONFIG["host_os"] =~ /mswin|windows|mingw/i
+          executable = executable.downcase
+          dir_entries = Dir.entries(path_entry)
+          dir_entries.find do |entry|
+            path = "#{path_entry}/#{entry}"
+            entry = entry.downcase
+            if ((entry == executable) or
+                (entry == "#{executable}.exe") or
+                (entry == "#{executable}.com") or
+                (entry == "#{executable}.bat")) and is_executable[path]
+              return path
+            end
+          end
+        else
+          path = "#{path_entry}/#{executable}"
+          return path if is_executable[path]
+        end
+      end
+
     end
   end
 end

spec/rscons/util_spec.rb

@@ -55,5 +55,61 @@ module Rscons
       end
     end
 
+    describe ".find_executable" do
+      context "when given a path with directory components" do
+        it "returns the path if it is executable" do
+          expect(File).to receive(:file?).with("a/path").and_return(true)
+          expect(File).to receive(:executable?).with("a/path").and_return(true)
+          expect(Util.find_executable("a/path")).to eq "a/path"
+        end
+
+        it "returns nil if the path is not executable" do
+          expect(File).to receive(:file?).with("a/path").and_return(true)
+          expect(File).to receive(:executable?).with("a/path").and_return(false)
+          expect(Util.find_executable("a/path")).to be_nil
+        end
+      end
+
+      context "when given a program name without directory components" do
+        context "on Windows" do
+          before(:each) do
+            stub_const("File::PATH_SEPARATOR", ";")
+            stub_const("RbConfig::CONFIG", "host_os" => "mingw")
+            expect(ENV).to receive(:[]).with("PATH").and_return("C:\\bin;C:\\Windows")
+            allow(Dir).to receive(:entries).with("C:\\bin").and_return(%w[one.com])
+            allow(Dir).to receive(:entries).with("C:\\Windows").and_return(%w[two.exe Three.bat])
+          end
+
+          it "returns a path to a .exe found" do
+            expect(File).to receive(:file?).with("C:\\Windows/two.exe").and_return(true)
+            expect(File).to receive(:executable?).with("C:\\Windows/two.exe").and_return(true)
+            expect(Util.find_executable("two")).to eq "C:\\Windows/two.exe"
+          end
+
+          it "returns a path to a .exe found including extension" do
+            expect(File).to receive(:file?).with("C:\\Windows/two.exe").and_return(true)
+            expect(File).to receive(:executable?).with("C:\\Windows/two.exe").and_return(true)
+            expect(Util.find_executable("TWO.EXE")).to eq "C:\\Windows/two.exe"
+          end
+
+          it "returns a path to a .com found" do
+            expect(File).to receive(:file?).with("C:\\bin/one.com").and_return(true)
+            expect(File).to receive(:executable?).with("C:\\bin/one.com").and_return(true)
+            expect(Util.find_executable("ONE")).to eq "C:\\bin/one.com"
+          end
+
+          it "returns a path to a .bat found" do
+            expect(File).to receive(:file?).with("C:\\Windows/Three.bat").and_return(true)
+            expect(File).to receive(:executable?).with("C:\\Windows/Three.bat").and_return(true)
+            expect(Util.find_executable("three")).to eq "C:\\Windows/Three.bat"
+          end
+
+          it "returns nil when nothing is found" do
+            expect(Util.find_executable("notthere")).to be_nil
+          end
+        end
+      end
+    end
+
   end
 end