Fix: Modernize for Crystal 1.20 and add ameba linting

.ameba.yml

@@ -0,0 +1,6 @@
+Naming/BlockParameterName:
+  Enabled: false
+Metrics/CyclomaticComplexity:
+  Enabled: false
+Documentation/DocumentationAdmonition:
+  Enabled: false

shard.yml

@@ -27,3 +27,6 @@ development_dependencies:
   spectator:
     gitlab: arctic-fox/spectator
     version: ~> 0.11.3
+  ameba:
+    github: crystal-ameba/ameba
+    version: ~> 1.6.0

spec/migration_spec.cr

@@ -101,5 +101,5 @@ baz;")
 end
 
 def statements(migration, direction)
-  migration.statements(direction).map { |stmt| stmt.strip }
+  migration.statements(direction).map(&.strip)
 end

src/micrate.cr

@@ -14,13 +14,11 @@ module Micrate
   end
 
   def self.dbversion(db)
-    begin
-      rows = DB.get_versions_last_first_order(db)
-      return extract_dbversion(rows)
-    rescue Exception
-      DB.create_migrations_table(db)
-      return 0
-    end
+    rows = DB.get_versions_last_first_order(db)
+    extract_dbversion(rows)
+  rescue Exception
+    DB.create_migrations_table(db)
+    0
   end
 
   def self.up(db)
@@ -32,7 +30,7 @@ module Micrate
     end
 
     current = dbversion(db)
-    target = all_migrations.keys.sort.last
+    target = all_migrations.keys.sort!.last
     migrate(all_migrations, current, target, db)
   end
 
@@ -85,7 +83,7 @@ module Micrate
     Dir.mkdir_p dir
     File.write(filename, migration_template)
 
-    return filename
+    filename
   end
 
   def self.connection_url=(connection_url)
@@ -150,7 +148,7 @@ module Micrate
       # the given version is (likely) valid but we didn't find
       # anything before it.
       # return value must reflect that no migrations have been applied.
-      return 0
+      0
     else
       raise "no previous version found"
     end
@@ -161,7 +159,7 @@ module Micrate
       .select { |name| File.file? File.join(migrations_dir, name) }
       .select { |name| /^\d+.+\.sql$/ =~ name }
       .map { |name| Migration.from_file(name) }
-      .index_by { |migration| migration.version }
+      .index_by(&.version)
   end
 
   def self.migration_plan(status : Hash(Migration, Time?), current : Int, target : Int, direction)
@@ -177,12 +175,12 @@ module Micrate
 
     if direction == :forward
       all_versions.keys
-        .sort
+        .sort!
         .select { |v| v > current && v <= target }
     else
       all_versions.keys
-        .sort
-        .reverse
+        .sort!
+        .reverse!
         .select { |v| v <= current && v > target }
     end
   end
@@ -204,7 +202,7 @@ module Micrate
       end
     end
 
-    return 0
+    0
   end
 
   class UnorderedMigrationsException < Exception

src/micrate/cli.cr

@@ -11,7 +11,7 @@ module Micrate
         File.delete(path)
         Log.info { "Deleted file #{path}" }
       else
-        name = set_database_to_schema url
+        name = extract_schema_name url
         Micrate::DB.connect do |db|
           db.exec "DROP DATABASE IF EXISTS #{name};"
         end
@@ -24,15 +24,15 @@ module Micrate
       if url.starts_with? "sqlite3:"
         Log.info { "For sqlite3, the database will be created during the first migration." }
       else
-        name = set_database_to_schema url
+        name = extract_schema_name url
         Micrate::DB.connect do |db|
           db.exec "CREATE DATABASE #{name};"
         end
         Log.info { "Created database #{name}" }
       end
     end
 
-    def self.set_database_to_schema(url)
+    def self.extract_schema_name(url)
       uri = URI.parse(url)
       if path = uri.path
         Micrate::DB.connection_url = url.gsub(path, "/#{uri.scheme}")

src/micrate/db.cr

@@ -11,13 +11,11 @@ module Micrate
     end
 
     def self.connect
-      validate_connection_url
-      ::DB.connect(self.connection_url.not_nil!)
+      ::DB.connect(valid_connection_url)
     end
 
-    def self.connect(&block)
-      validate_connection_url
-      ::DB.open self.connection_url.not_nil! do |db|
+    def self.connect(&)
+      ::DB.open valid_connection_url do |db|
         yield db
       end
     end
@@ -50,14 +48,15 @@ module Micrate
     end
 
     private def self.dialect
-      validate_connection_url
-      @@dialect ||= Dialect.from_connection_url(self.connection_url.not_nil!)
+      @@dialect ||= Dialect.from_connection_url(valid_connection_url)
     end
 
-    private def self.validate_connection_url
-      if !self.connection_url
+    private def self.valid_connection_url : String
+      url = self.connection_url
+      if !url
         raise "No database connection URL is configured. Please set the DATABASE_URL environment variable."
       end
+      url
     end
   end
 end

src/micrate/migration.cr

@@ -77,8 +77,8 @@ module Micrate
 
     def self.from_version(version)
       file_name = Dir.entries(Micrate.migrations_dir)
-        .find { |name| name.starts_with? version.to_s }
-        .not_nil!
+        .find(&.starts_with?(version.to_s))
+
       self.from_file(file_name)
     end
   end