✨ : add HCL parsing for outputs

src/main/antlr4/io/codeka/gaia/hcl/antlr/hcl.g4

@@ -6,39 +6,67 @@ file
 
 directive
   : variableDirective
+  | outputDirective
   ;
 
 variableDirective
   : 'variable' identifier variableBlock
   ;
 
 variableBlock
-  : '{' type? description? r_default? '}'
+  : '{' type? variableDescription? r_default? '}'
+  ;
+
+outputDirective
+  : 'output' identifier outputBlock
+  ;
+
+outputBlock
+  : '{' outputValue? outputDescription? sensitive? '}'
+  ;
+
+outputValue
+  : 'value' '=' expression
+  ;
+
+outputDescription
+  : 'description' '=' STRING
+  ;
+
+sensitive
+  : 'sensitive' '=' BOOLEAN
   ;
 
 type
   : 'type' '=' TYPE
   ;
 
-description
+variableDescription
   : 'description' '=' STRING
   ;
 
 r_default
-  : 'default' '=' defaultValue
+  : 'default' '=' expression
   ;
 
-defaultValue
+expression
   : STRING
   | NUMBER
-  | 'true'
-  | 'false'
+  | BOOLEAN
+  | UNQUOTED_STRING
   ;
 
 identifier
   : STRING
   ;
 
+BOOLEAN
+  : 'true'
+  | '"true"'
+  | 'false'
+  | '"false"'
+  ;
+
 TYPE
   : 'string'
   | '"string"'
@@ -48,6 +76,10 @@ TYPE
   | '"bool"'
   ;
 
+UNQUOTED_STRING
+  : [a-zA-Z0-9_.[\]-]+
+  ;
+
 /**
  * STRING Lexer Rule comes from the JSON grammar
  * https://github.com/antlr/grammars-v4/blob/master/json/JSON.g4

src/main/java/io/codeka/gaia/hcl/HclTreeListener.kt

@@ -7,27 +7,50 @@ import java.util.*
 class HclTreeListener : hclBaseListener() {
 
     var variables: MutableList<Variable> = LinkedList()
+    var outputs: MutableList<Output> = LinkedList()
 
-    private var current: Variable = Variable()
+    private var currentVariable: Variable = Variable()
+    private var currentOutput:Output = Output()
 
     override fun enterVariableDirective(ctx: hclParser.VariableDirectiveContext) {
-        this.current = Variable()
-        this.current.name = ctx.identifier().text
+        this.currentVariable = Variable()
+        this.currentVariable.name = ctx.identifier().text
     }
 
     override fun exitVariableDirective(ctx: hclParser.VariableDirectiveContext) {
-        this.variables.add(this.current)
+        this.variables.add(this.currentVariable)
     }
 
     override fun enterType(ctx: hclParser.TypeContext) {
-        this.current.type = ctx.TYPE().text
+        this.currentVariable.type = ctx.TYPE().text
     }
 
-    override fun enterDescription(ctx: hclParser.DescriptionContext) {
-        this.current.description = ctx.STRING().text
+    override fun enterVariableDescription(ctx: hclParser.VariableDescriptionContext) {
+        this.currentVariable.description = ctx.STRING().text
     }
 
     override fun enterR_default(ctx: hclParser.R_defaultContext) {
-        this.current.default = ctx.defaultValue().text
+        this.currentVariable.default = ctx.expression().text
     }
+
+    override fun enterOutputDirective(ctx: hclParser.OutputDirectiveContext) {
+        this.currentOutput = Output(name = ctx.identifier().text)
+    }
+
+    override fun exitOutputDirective(ctx: hclParser.OutputDirectiveContext) {
+        this.outputs.add(this.currentOutput)
+    }
+
+    override fun enterOutputValue(ctx: hclParser.OutputValueContext) {
+        this.currentOutput.value = ctx.expression().text
+    }
+
+    override fun enterOutputDescription(ctx: hclParser.OutputDescriptionContext) {
+        this.currentOutput.description = ctx.STRING().text
+    }
+
+    override fun enterSensitive(ctx: hclParser.SensitiveContext) {
+        this.currentOutput.sensitive = ctx.BOOLEAN().text
+    }
+
 }

src/main/java/io/codeka/gaia/hcl/Variable.kt → src/main/java/io/codeka/gaia/hcl/HclTypes.kt

@@ -2,3 +2,5 @@ package io.codeka.gaia.hcl
 
 data class Variable(var name: String = "", var type: String = "", var description: String = "", var default: String = "");
 
+data class Output(var name: String = "", var value: String = "", var description: String = "", var sensitive: String = "false");
+

src/test/java/io/codeka/gaia/hcl/HCLParserTest.java

@@ -16,7 +16,7 @@
 class HCLParserTest {
 
     @Test
-    void parsing_variable_shouldWork() throws IOException {
+    void parsing_variables_shouldWork() throws IOException {
         // given
         // loading test file
         CharStream charStream = CharStreams.fromStream(new ClassPathResource("hcl/variables.tf").getInputStream());
@@ -44,4 +44,32 @@ void parsing_variable_shouldWork() throws IOException {
         assertThat(hclTreeListener.getVariables()).contains(stringVar, numberVar, boolVar);
     }
 
+    @Test
+    void parsing_outputs_shouldWork() throws IOException {
+        // given
+        // loading test file
+        CharStream charStream = CharStreams.fromStream(new ClassPathResource("hcl/outputs.tf").getInputStream());
+
+        // configuring antlr lexer
+        hclLexer lexer = new hclLexer(charStream);
+
+        // configuring antlr parser
+        CommonTokenStream tokenStream = new CommonTokenStream(lexer);
+        hclParser parser = new hclParser(tokenStream);
+
+        // when
+        // walk the AST
+        ParseTreeWalker walker = new ParseTreeWalker();
+        var hclTreeListener = new HclTreeListener();
+        walker.walk(hclTreeListener, parser.file());
+
+        // then
+        assertThat(hclTreeListener.getOutputs()).hasSize(2);
+
+        var output1 = new Output("\"instance_ip_addr\"", "\"${aws_instance.server.private_ip}\"", "\"The private IP address of the main server instance.\"", "false");
+        var output2 = new Output("\"db_password\"", "aws_db_instance.db[1].password", "\"The password for logging in to the database.\"", "true");
+
+        assertThat(hclTreeListener.getOutputs()).contains(output1, output2);
+    }
+
 }

src/test/resources/hcl/outputs.tf

@@ -0,0 +1,10 @@
+output "instance_ip_addr" {
+  value       = "${aws_instance.server.private_ip}"
+  description = "The private IP address of the main server instance."
+}
+
+output "db_password" {
+  value       = aws_db_instance.db[1].password
+  description = "The password for logging in to the database."
+  sensitive   = true
+}