Add type alias to TypeScript AST

6 files changed, 126 insertions, 1 deletions

diff --git a/hobgoblin/src/output/lang/typescript/ast.hob b/hobgoblin/src/output/lang/typescript/ast.hob
index ab305c6..e421996 100644
--- a/hobgoblin/src/output/lang/typescript/ast.hob
+++ b/hobgoblin/src/output/lang/typescript/ast.hob
@@ -16,6 +16,7 @@ sum TypescriptStatement {
     variant TypescriptClassDeclaration;
     variant TypescriptExportNamesStatement;
     variant TypescriptExpressionStatement;
+    variant TypescriptTypeAlias;
 }
 
 struct TypescriptClassDeclaration {
@@ -33,6 +34,11 @@ struct TypescriptExpressionStatement {
     field expression: TypescriptExpression;
 }
 
+struct TypescriptTypeAlias {
+    field name: TypescriptIdentifier;
+    field type: TypescriptExpression;
+}
+
 // == Class elements ==
 
 sum TypescriptClassElement {
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/TypescriptWriter.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/TypescriptWriter.java
index 93216bf..50d67bf 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/TypescriptWriter.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/TypescriptWriter.java
@@ -79,6 +79,10 @@ public class TypescriptWriter implements AutoCloseable {
             case TypescriptExpressionStatement expressionStatement -> {
                 this.writeExpressionStatement(expressionStatement);
             }
+
+            case TypescriptTypeAlias typeAlias -> {
+                this.writeTypeAlias(typeAlias);
+            }
         }
     }
 
@@ -136,6 +140,14 @@ public class TypescriptWriter implements AutoCloseable {
         this.writer.write(";");
     }
 
+    private void writeTypeAlias(TypescriptTypeAlias typeAlias) throws IOException {
+        this.writer.write("type ");
+        this.writeIdentifier(typeAlias.name());
+        this.writer.write(" = ");
+        this.writeExpression(typeAlias.type());
+        this.writer.write(";");
+    }
+
     // == Class elements ==
 
     void writeClassElement(TypescriptClassElement element) throws IOException {
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptStatement.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptStatement.java
index 6d24493..5d687c0 100644
--- a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptStatement.java
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptStatement.java
@@ -5,7 +5,7 @@ package org.zwobble.hobgoblin.compiler.output.lang.typescript.ast;
 // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptStatement imports
 // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptStatement imports
 
-public sealed interface TypescriptStatement permits org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptClassDeclaration, org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptExportNamesStatement, org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptExpressionStatement {
+public sealed interface TypescriptStatement permits org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptClassDeclaration, org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptExportNamesStatement, org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptExpressionStatement, org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias {
     public interface Builder {
         public org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptStatement build();
 
diff --git a/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptTypeAlias.java b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptTypeAlias.java
new file mode 100644
index 0000000..0031a83
--- /dev/null
+++ b/src/main/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptTypeAlias.java
@@ -0,0 +1,46 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.typescript.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias imports
+
+public record TypescriptTypeAlias(
+    org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptIdentifier name,
+    org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptExpression type
+) implements org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptStatement {
+    public static org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder arbitrary() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder(org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptIdentifier.arbitrary().build(), org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptNumberLiteral.arbitrary().build());
+    }
+
+    public record Builder(
+        org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptIdentifier name,
+        org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptExpression type
+    ) implements org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptStatement.Builder {
+        public org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias build() {
+            return new org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias(name, type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder withName(org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptIdentifier name) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder(name, type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder withName(org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptIdentifier.Builder name) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder(name.build(), type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder withType(org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptExpression type) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder(name, type);
+        }
+
+        public org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder withType(org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptExpression.Builder type) {
+            return new org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder(name, type.build());
+        }
+
+        // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder body
+        // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.Builder body
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias body
+}
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/TypescriptWriterTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/TypescriptWriterTests.java
index c7d2e2d..56cbc6c 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/TypescriptWriterTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/TypescriptWriterTests.java
@@ -159,6 +159,20 @@ public class TypescriptWriterTests {
         assertThat(string, equalTo("42.0;"));
     }
 
+    // === Type aliases ===
+
+    @Test
+    public void typeAlias() throws IOException {
+        var typescript = TypescriptTypeAlias.arbitrary()
+            .withName(id("X"))
+            .withType(ref("number"))
+            .build();
+
+        var string = write(writer -> writer.writeStatement(typescript));
+
+        assertThat(string, equalTo("type X = number;"));
+    }
+
     // == Class elements ==
 
     // === Class constructors ===
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptTypeAliasMatcher.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptTypeAliasMatcher.java
new file mode 100644
index 0000000..039e67b
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/typescript/ast/TypescriptTypeAliasMatcher.java
@@ -0,0 +1,47 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.typescript.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher imports
+
+public final class TypescriptTypeAliasMatcher implements org.zwobble.precisely.Matcher<java.lang.Object> {
+    public static org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher isTypescriptTypeAlias() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher(java.util.List.of());
+    }
+
+    private final java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias>> submatchers;
+
+    private TypescriptTypeAliasMatcher(
+        java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias>> submatchers
+    ) {
+        this.submatchers = submatchers;
+    }
+
+    public org.zwobble.precisely.MatchResult match(java.lang.Object actual) {
+        return this.toMatcher().match(actual);
+    }
+
+    public org.zwobble.precisely.TextTree describe() {
+        return this.toMatcher().describe();
+    }
+
+    private org.zwobble.precisely.Matcher<java.lang.Object> toMatcher() {
+        return org.zwobble.precisely.Matchers.instanceOf(org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias.class, this.submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher withName(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptIdentifier> name) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("name", org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias::name, (org.zwobble.precisely.Matcher) name));
+        return new org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher(submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher withType(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptExpression> type) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("type", org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAlias::type, (org.zwobble.precisely.Matcher) type));
+        return new org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher(submatchers);
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.typescript.ast.TypescriptTypeAliasMatcher body
+}