From 371414e8557eab9f4c5efd4f4f60f1472052f732 Mon Sep 17 00:00:00 2001
From: Margret Riegert <margret@eowyn.net>
Date: Wed, 15 Jan 2025 00:18:01 -0500
Subject: [PATCH] Add support for linting ECR files (#536)

---
 README.md                 |  1 +
 spec/ameba/source_spec.cr | 26 ++++++++++++++++++++++++++
 src/ameba.cr              |  4 ++++
 src/ameba/config.cr       |  7 ++++++-
 src/ameba/glob_utils.cr   |  9 ++++++++-
 src/ameba/source.cr       | 16 ++++++++++++++++
 6 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 58b74e6e0..729ecfca0 100644
--- a/README.md
+++ b/README.md
@@ -174,6 +174,7 @@ In this example we define default globs and exclude `src/compiler` folder:
 ``` yaml
 Globs:
   - "**/*.cr"
+  - "**/*.ecr"
   - "!lib"
 
 Excluded:
diff --git a/spec/ameba/source_spec.cr b/spec/ameba/source_spec.cr
index 8c8b1a1b4..4b1cd4e3b 100644
--- a/spec/ameba/source_spec.cr
+++ b/spec/ameba/source_spec.cr
@@ -70,5 +70,31 @@ module Ameba
           CRYSTAL
       end
     end
+
+    if Ameba.ecr_supported?
+      describe "#ast" do
+        it "parses an ECR file" do
+          source = Source.new <<-ECR, "filename.ecr"
+            hello <%= "world" %>
+            ECR
+
+          source.ast.to_s.should eq(<<-CRYSTAL)
+            __str__ << "hello "
+            ("world").to_s(__str__)
+
+            CRYSTAL
+        end
+
+        it "raises an exception when ECR parsing fails" do
+          source = Source.new <<-ECR, "filename.ecr"
+            hello <%= "world" >
+            ECR
+
+          expect_raises(Crystal::SyntaxException) do
+            source.ast
+          end
+        end
+      end
+    end
   end
 end
diff --git a/src/ameba.cr b/src/ameba.cr
index e675939ac..94b9f141c 100644
--- a/src/ameba.cr
+++ b/src/ameba.cr
@@ -40,4 +40,8 @@ module Ameba
   def run(config = Config.load)
     Runner.new(config).run
   end
+
+  def self.ecr_supported? : Bool
+    {{ compare_versions(Crystal::VERSION, "1.15.0") >= 0 }}
+  end
 end
diff --git a/src/ameba/config.cr b/src/ameba/config.cr
index 89a710e53..6b82e7aba 100644
--- a/src/ameba/config.cr
+++ b/src/ameba/config.cr
@@ -1,5 +1,6 @@
 require "semantic_version"
 require "yaml"
+require "ecr/processor"
 require "./glob_utils"
 
 # A configuration entry for `Ameba::Runner`.
@@ -62,6 +63,10 @@ class Ameba::Config
     !lib
   )
 
+  if Ameba.ecr_supported?
+    DEFAULT_GLOBS << "**/*.ecr"
+  end
+
   getter rules : Array(Rule::Base)
   property severity = Severity::Convention
 
@@ -167,7 +172,7 @@ class Ameba::Config
   # ```
   # config = Ameba::Config.load
   # config.sources # => list of default sources
-  # config.globs = ["**/*.cr"]
+  # config.globs = ["**/*.cr", "**/*.ecr"]
   # config.excluded = ["spec"]
   # config.sources # => list of sources pointing to files found by the wildcards
   # ```
diff --git a/src/ameba/glob_utils.cr b/src/ameba/glob_utils.cr
index 63dd67cc7..ef6c6c6f9 100644
--- a/src/ameba/glob_utils.cr
+++ b/src/ameba/glob_utils.cr
@@ -24,7 +24,14 @@ module Ameba
     def expand(globs)
       globs
         .flat_map do |glob|
-          glob += "/**/*.cr" if File.directory?(glob)
+          if File.directory?(glob)
+            glob += "/**/*.cr"
+
+            if Ameba.ecr_supported?
+              glob += "/**/*.ecr"
+            end
+          end
+
           Dir[glob]
         end
         .uniq!
diff --git a/src/ameba/source.cr b/src/ameba/source.cr
index 29d9d1990..010638feb 100644
--- a/src/ameba/source.cr
+++ b/src/ameba/source.cr
@@ -57,6 +57,22 @@ module Ameba
     # source.ast
     # ```
     getter ast : Crystal::ASTNode do
+      code = @code
+
+      if Ameba.ecr_supported? && @path.ends_with?(".ecr")
+        begin
+          code = ECR.process_string(code, @path)
+        rescue ex : ECR::Lexer::SyntaxException
+          # Need to rescue to add the filename
+          raise Crystal::SyntaxException.new(
+            ex.message,
+            ex.line_number,
+            ex.column_number,
+            @path
+          )
+        end
+      end
+
       Crystal::Parser.new(code)
         .tap(&.wants_doc = true)
         .tap(&.filename = path)