Raise on invalid file path

spec/ameba/cli/cmd_spec.cr

@@ -7,9 +7,39 @@ module Ameba::CLI
   describe "Cmd" do
     describe ".run" do
       it "runs ameba" do
-        r = CLI.run %w[-f silent file.cr]
+        r = CLI.run ["-f", "silent", "--only", "Lint/ComparisonToBoolean", __FILE__]
         r.should be_true
       end
+
+      it "raises when a non-existent file is provided" do
+        expect_raises(Exception, "No files found matching `not_there.cr`") do
+          CLI.run %w[-f silent not_there.cr]
+        end
+      end
+
+      it "raises when a glob matches no files" do
+        expect_raises(Exception, "No files found matching `#{Path["nonexistent_dir", "**", "*.cr"].relative_to(Dir.current)}`") do
+          CLI.run %w[-f silent nonexistent_dir/**/*.cr]
+        end
+      end
+
+      context "with `--ignore-unmatched-paths` flag" do
+        it "does not raise when a non-existent file is provided" do
+          r = CLI.run %w[-f silent --ignore-unmatched-paths not_there.cr]
+          r.should be_true
+        end
+
+        it "does not raise when a non-matching glob is provided" do
+          r = CLI.run %w[-f silent --ignore-unmatched-paths nonexistent_dir/**/*.cr]
+          r.should be_true
+        end
+      end
+
+      it "does not raise when reading from STDIN" do
+        # STDIN mode should bypass glob validation
+        opts = CLI.parse_args %w[--stdin-filename foo.cr]
+        opts.stdin_filename.should_not be_nil
+      end
     end
 
     describe ".parse_args" do
@@ -91,6 +121,11 @@ module Ameba::CLI
         opts.colors?.should be_false
       end
 
+      it "accepts --ignore-unmatched-paths flag" do
+        opts = CLI.parse_args %w[--ignore-unmatched-paths]
+        opts.ignore_unmatched_paths?.should be_true
+      end
+
       it "accepts --without-affected-code flag" do
         opts = CLI.parse_args %w[--without-affected-code]
         opts.without_affected_code?.should be_true

src/ameba/cli/cmd.cr

@@ -24,6 +24,7 @@ module Ameba::CLI
     property? all = false
     property? colors = true
     property? without_affected_code = false
+    property? ignore_unmatched_paths = false
     property? autocorrect = false
   end
 
@@ -69,6 +70,8 @@ module Ameba::CLI
         return true
       end
 
+      validate_globs(opts, config.root)
+
       runner = Ameba.run(config)
 
       if location_to_explain
@@ -186,6 +189,11 @@ module Ameba::CLI
         opts.without_affected_code = true
       end
 
+      parser.on("--ignore-unmatched-paths",
+        "Do not report unmatched path patterns") do
+        opts.ignore_unmatched_paths = true
+      end
+
       parser.on("--no-color", "Disable colors") do
         opts.colors = false
       end
@@ -308,6 +316,17 @@ module Ameba::CLI
     opts.formatter = :silent
   end
 
+  private def validate_globs(opts, root) : Nil
+    return if opts.ignore_unmatched_paths?
+    return if opts.stdin_filename
+    return unless globs = opts.globs
+
+    globs.each do |glob|
+      next unless GlobUtils.expand({glob}, root).empty?
+      raise "No files found matching `#{Path[glob].relative_to(Dir.current)}`"
+    end
+  end
+
   private def configure_explain_opts(loc, opts) : Nil
     location_to_explain = parse_explain_location(loc)