using error reporter from environment to handle syntax errors

Sources/Environment.swift

@@ -3,9 +3,15 @@ public struct Environment {
   public var extensions: [Extension]
 
   public var loader: Loader?
+  public var errorReporter: ErrorReporter
 
-  public init(loader: Loader? = nil, extensions: [Extension]? = nil, templateClass: Template.Type = Template.self) {
+  public init(loader: Loader? = nil,
+              extensions: [Extension]? = nil,
+              templateClass: Template.Type = Template.self,
+              errorReporter: ErrorReporter = SimpleErrorReporter()) {
+    
     self.templateClass = templateClass
+    self.errorReporter = errorReporter
     self.loader = loader
     self.extensions = (extensions ?? []) + [DefaultExtension()]
   }
@@ -28,11 +34,21 @@ public struct Environment {
 
   public func renderTemplate(name: String, context: [String: Any]? = nil) throws -> String {
     let template = try loadTemplate(name: name)
-    return try template.render(context)
+    return try render(template: template, context: context)
   }
 
   public func renderTemplate(string: String, context: [String: Any]? = nil) throws -> String {
     let template = templateClass.init(templateString: string, environment: self)
-    return try template.render(context)
+    return try render(template: template, context: context)
+  }
+  
+  func render(template: Template, context: [String: Any]?) throws -> String {
+    errorReporter.context = ErrorReporterContext(template: template)
+    do {
+      return try template.render(context)
+    } catch {
+      try errorReporter.report(error: error)
+      return ""
+    }
   }
 }

Tests/StencilTests/EnvironmentSpec.swift

@@ -1,5 +1,5 @@
 import Spectre
-import Stencil
+@testable import Stencil
 
 
 func testEnvironment() {
@@ -32,6 +32,46 @@ func testEnvironment() {
 
       try expect(result) == "here"
     }
+    
+    func expectedSyntaxError(token: String, template: Template, description: String) -> TemplateSyntaxError {
+      var error = TemplateSyntaxError(description)
+      error.lexeme = Token.block(value: token, at: template.templateString.range(of: token)!)
+      let context = ErrorReporterContext(template: template)
+      error = environment.errorReporter.contextAwareError(error, context: context) as! TemplateSyntaxError
+      print(error)
+      return error
+    }
+    
+    $0.it("throws syntax error on invalid for tag syntax") {
+      let template: Template = "Hello {% for name in %}{{ name }}, {% endfor %}!"
+      let error = expectedSyntaxError(
+        token: "{% for name in %}",
+        template: template,
+        description: "'for' statements should use the following syntax 'for x in y where condition'."
+      )
+      try expect(try environment.renderTemplate(string: template.templateString, context:["names": ["Bob", "Alice"]])).toThrow(error)
+    }
+    
+    $0.it("throws syntax error on missing endfor") {
+      let template: Template = "{% for name in names %}{{ name }}"
+      let error = expectedSyntaxError(
+        token: "{% for name in names %}",
+        template: template,
+        description: "`endfor` was not found."
+      )
+      try expect(try environment.renderTemplate(string: template.templateString, context: ["names": ["Bob", "Alice"]])).toThrow(error)
+    }
+    
+    $0.it("throws syntax error on unknown tag") {
+      let template: Template = "{% for name in names %}{{ name }}{% end %}"
+      let error = expectedSyntaxError(
+        token: "{% end %}",
+        template: template,
+        description: "Unknown template tag 'end'"
+      )
+      try expect(try environment.renderTemplate(string: template.templateString, context: ["names": ["Bob", "Alice"]])).toThrow(error)
+    }
+    
   }
 }
 

Tests/StencilTests/TemplateSpec.swift

@@ -15,30 +15,6 @@ func testTemplate() {
         let result = try template.render([ "name": "Kyle" ])
         try expect(result) == "Hello World"
     }
-
-    $0.it("throws syntax error on invalid for tag syntax") {
-      let template: Template = "Hello {% for name in %}{{ name }}, {% endfor %}!"
-      var error = TemplateSyntaxError("'for' statements should use the following syntax 'for x in y where condition'.")
-      error.token = Token.block(value: "{% for name in %}", at: template.templateString.range(of: "{% for name in %}")!)
-      error = error.contextAwareError(templateName: nil, templateContent: template.templateString)!
-      try expect(try template.render(["names": ["Bob", "Alice"]])).toThrow(error)
-    }
-    
-    $0.it("throws syntax error on missing endfor") {
-      let template: Template = "{% for name in names %}{{ name }}"
-      var error = TemplateSyntaxError("`endfor` was not found.")
-      error.token = Token.block(value: "{% for name in names %}", at: template.templateString.range(of: "{% for name in names %}")!)
-      error = error.contextAwareError(templateName: nil, templateContent: template.templateString)!
-      try expect(try template.render(["names": ["Bob", "Alice"]])).toThrow(error)
-    }
-
-    $0.it("throws syntax error on unknown tag") {
-      let template: Template = "{% for name in names %}{{ name }}{% end %}"
-      var error = TemplateSyntaxError("Unknown template tag 'end'")
-      error.token = Token.block(value: "{% end %}", at: template.templateString.range(of: "{% end %}")!)
-      error = error.contextAwareError(templateName: nil, templateContent: template.templateString)!
-      try expect(try template.render(["names": ["Bob", "Alice"]])).toThrow(error)
-    }
     
   }
 }