Escape $ chars in doc strings

Author: kstich

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/TypeScriptWriter.java

@@ -179,11 +179,14 @@ TypeScriptWriter writeDocs(Runnable runnable) {
     /**
      * Writes documentation comments from a string.
      *
+     * <p>This function escapes "$" characters so formatters are not run.
+     *
      * @param docs Documentation to write.
      * @return Returns the writer.
      */
     public TypeScriptWriter writeDocs(String docs) {
-        writeDocs(() -> write(docs));
+        // Docs can have valid $ characters that shouldn't run through formatters.
+        writeDocs(() -> write(docs.replace("$", "$$")));
         return this;
     }
 

smithy-typescript-codegen/src/test/java/software/amazon/smithy/typescript/codegen/TypeScriptWriterTest.java

@@ -25,6 +25,17 @@ public void doesNotAddNewlineBetweenManagedAndExplicitImports() {
         assertThat(result, equalTo("import { Baz } from \"hello\";\nimport { Foo } from \"baz\";\n"));
     }
 
+    @Test
+    public void escapesDollarInDocStrings() {
+        String docs = "This is $ valid documentation.";
+
+        TypeScriptWriter writer = new TypeScriptWriter("foo");
+        writer.writeDocs(docs);
+        String result = writer.toString();
+
+        assertThat(result, equalTo("/**\n * " + docs + "\n */\n"));
+    }
+
     @Test
     public void addsFormatterForSymbols() {
         // TODO