fix(android): allow and escape Kotlin keyword as package identifier

.changes/android-kotlin-keyword-as-ident.md

@@ -0,0 +1,5 @@
+---
+"cargo-mobile2": "patch"
+---
+
+On Android, allows using Kotlin keywords as identifiers and escape them in templates.

src/config/app/identifier.rs

@@ -3,9 +3,9 @@ use std::error::Error;
 use std::fmt;
 
 static RESERVED_PACKAGE_NAMES: [&str; 2] = ["kotlin", "java"];
-static RESERVED_KEYWORDS: [&str; 63] = [
+// https://docs.oracle.com/javase/tutorial/java/nutsandbolts/_keywords.html
+static RESERVED_JAVA_KEYWORDS: [&str; 53] = [
     "abstract",
-    "as",
     "assert",
     "boolean",
     "break",
@@ -27,21 +27,17 @@ static RESERVED_KEYWORDS: [&str; 63] = [
     "finally",
     "float",
     "for",
-    "fun",
     "goto",
     "if",
     "implements",
     "import",
     "instanceof",
-    "in",
     "int",
     "interface",
-    "is",
     "long",
     "native",
     "new",
     "null",
-    "object",
     "package",
     "private",
     "protected",
@@ -59,13 +55,8 @@ static RESERVED_KEYWORDS: [&str; 63] = [
     "transient",
     "true",
     "try",
-    "typealias",
-    "typeof",
-    "val",
-    "var",
     "void",
     "volatile",
-    "when",
     "while",
 ];
 
@@ -129,7 +120,7 @@ pub fn check_identifier_syntax(identifier_name: &str) -> Result<(), IdentifierEr
         if label.is_empty() {
             return Err(IdentifierError::EmptyLabel);
         }
-        if RESERVED_KEYWORDS.contains(&label) {
+        if RESERVED_JAVA_KEYWORDS.contains(&label) {
             return Err(IdentifierError::ReservedKeyword {
                 keyword: label.to_owned(),
             });

src/config/app/mod.rs

@@ -222,6 +222,20 @@ impl App {
             .join(".")
     }
 
+    pub fn android_identifier_escape_kotlin_keyword(&self) -> String {
+        self.reverse_identifier()
+            .split('.')
+            .map(|s| {
+                if crate::reserved_names::KOTLIN_ONLY_KEYWORDS.contains(&s) {
+                    format!("`{}`", s)
+                } else {
+                    s.to_string()
+                }
+            })
+            .collect::<Vec<_>>()
+            .join(".")
+    }
+
     pub fn manifest_path(&self) -> PathBuf {
         self.root_dir().join("Cargo.toml")
     }

src/lib.rs

@@ -13,7 +13,7 @@ pub mod init;
 pub mod opts;
 pub mod os;
 mod project;
-mod reserved_names;
+pub mod reserved_names;
 pub mod target;
 mod templating;
 pub mod update;

src/reserved_names/mod.rs

@@ -19,6 +19,19 @@ pub static WINDOWS: &[&str] = &[
 
 pub static ARTIFACTS: &[&str] = &["deps", "examples", "build", "incremental"];
 
+pub static KOTLIN_ONLY_KEYWORDS: &[&str] = &[
+    "as",
+    "fun",
+    "in",
+    "is",
+    "object",
+    "typealias",
+    "typeof",
+    "val",
+    "var",
+    "when",
+];
+
 pub fn in_keywords(s: impl AsRef<str>) -> bool {
     KEYWORDS.contains(&s.as_ref())
 }

src/templating/init.rs

@@ -6,6 +6,7 @@ use crate::{
         Bicycle, EscapeFn, HelperDef, JsonMap,
     },
     config::{app, Config},
+    reserved_names::KOTLIN_ONLY_KEYWORDS,
     util::{self, Git},
 };
 use std::collections::HashMap;
@@ -122,6 +123,28 @@ fn reverse_domain_snake_case(
         .map_err(Into::into)
 }
 
+fn escape_kotlin_keyword(
+    helper: &Helper,
+    _: &Handlebars,
+    _: &Context,
+    _: &mut RenderContext,
+    out: &mut dyn Output,
+) -> HelperResult {
+    let escaped_result = get_str(helper)
+        .split('.')
+        .map(|s| {
+            if KOTLIN_ONLY_KEYWORDS.contains(&s) {
+                format!("`{}`", s)
+            } else {
+                s.to_string()
+            }
+        })
+        .collect::<Vec<_>>()
+        .join(".");
+
+    out.write(&escaped_result).map_err(Into::into)
+}
+
 fn app_root(ctx: &Context) -> Result<&str, RenderErrorReason> {
     let app_root = ctx
         .data()
@@ -219,6 +242,7 @@ pub fn init(config: Option<&Config>) -> Bicycle {
                 "reverse-domain-snake-case",
                 Box::new(reverse_domain_snake_case),
             );
+            helpers.insert("escape-kotlin-keyword", Box::new(escape_kotlin_keyword));
             helpers.insert("dot-to-slash", Box::new(dot_to_slash));
             if config.is_some() {
                 // don't mix these up or very bad things will happen to all of us

templates/apps/wry/gen/android/app/src/main/kotlin/{{dot-to-slash (reverse-domain app.domain)}}/{{snake-case app.name}}/MainActivity.kt.hbs

@@ -1,3 +1,3 @@
-package {{reverse-domain app.identifier}}
+package {{escape-kotlin-keyword (reverse-domain app.identifier)}}
 
 class MainActivity : WryActivity()