From 0d1ee74ca63a73ba716fb95166c22ca29fef7f91 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Thu, 9 May 2024 17:35:27 -0400
Subject: [PATCH] Give a better error message when a referenced ptype has not
 been declared

---
 lib/propane/generator.rb | 12 ++++++++++++
 spec/propane_spec.rb     | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/lib/propane/generator.rb b/lib/propane/generator.rb
index 7c0444b..7611ad9 100644
--- a/lib/propane/generator.rb
+++ b/lib/propane/generator.rb
@@ -51,6 +51,7 @@ class Propane
       unless found_default
         raise Error.new("No patterns found for default mode")
       end
+      check_ptypes!
       # Add EOF token.
       @grammar.tokens << Token.new("$EOF", nil, nil)
       tokens_by_name = {}
@@ -131,6 +132,17 @@ class Propane
       @parser = Parser.new(@grammar, rule_sets, @log)
     end
 
+    # Check that any referenced ptypes have been defined.
+    def check_ptypes!
+      (@grammar.patterns + @grammar.tokens + @grammar.rules).each do |potor|
+        if potor.ptypename
+          unless @grammar.ptypes.include?(potor.ptypename)
+            raise Error.new("Error: Line #{potor.line_number}: ptype #{potor.ptypename} not declared. Declare with `ptype` statement.")
+          end
+        end
+      end
+    end
+
     # Generate and add rules for any optional components.
     def generate_optional_component_rules!(tokens_by_name)
       optional_rules_added = Set.new
diff --git a/spec/propane_spec.rb b/spec/propane_spec.rb
index ba09416..43b11d0 100644
--- a/spec/propane_spec.rb
+++ b/spec/propane_spec.rb
@@ -148,6 +148,42 @@ EOF
     expect(results.status).to_not eq 0
   end
 
+  it "raises an error when a pattern referenced ptype has not been defined" do
+    write_grammar <<EOF
+ptype yes = int;
+/foo/ (yes) <<
+>>
+/bar/ (no) <<
+>>
+EOF
+    results = run_propane(capture: true)
+    expect(results.stderr).to match /Error: Line 4: ptype no not declared\. Declare with `ptype` statement\./
+    expect(results.status).to_not eq 0
+  end
+
+  it "raises an error when a token referenced ptype has not been defined" do
+    write_grammar <<EOF
+ptype yes = int;
+token foo (yes);
+token bar (no);
+EOF
+    results = run_propane(capture: true)
+    expect(results.stderr).to match /Error: Line 3: ptype no not declared\. Declare with `ptype` statement\./
+    expect(results.status).to_not eq 0
+  end
+
+  it "raises an error when a rule referenced ptype has not been defined" do
+    write_grammar <<EOF
+ptype yes = int;
+token xyz;
+foo (yes) -> bar;
+bar (no) -> xyz;
+EOF
+    results = run_propane(capture: true)
+    expect(results.stderr).to match /Error: Line 4: ptype no not declared\. Declare with `ptype` statement\./
+    expect(results.status).to_not eq 0
+  end
+
   %w[d c].each do |language|
 
     context "#{language.upcase} language" do