automatic_edits: Use dotted notation within packages

CONFIG.md

@@ -109,15 +109,15 @@ If for some reason you don't want to sandbox a particular build script, you can
 just for that build script.
 
 ```toml
-[pkg.foo.build]
-sandbox.kind = "Disabled"
+[pkg.foo]
+build.sandbox.kind = "Disabled"
 ```
 
 If a build script needs network access, you can relax the sandbox to allow it as follows:
 
 ```toml
-[pkg.foo.build]
-sandbox.allow_network = true
+[pkg.foo]
+build.sandbox.allow_network = true
 ```
 
 Tests can also be run in a sandbox using the `cargo` subcommand, for example:
@@ -132,16 +132,16 @@ tests, with a sandbox if one is configured.
 The sandbox used for tests is configured under `pkg.{pkg-name}.test`. e.g.:
 
 ```toml
-[pkg.foo.test]
-sandbox.kind = "Disabled"
+[pkg.foo]
+test.sandbox.kind = "Disabled"
 ```
 
 Tests and build scripts already have write access to a temporary directory, however, if for some
 reason they need to write to some directory in your source folder, this can be permitted as follows:
 
 ```toml
-[pkg.foo.test]
-sandbox.bind_writable = [
+[pkg.foo]
+test.sandbox.bind_writable = [
     "test_outputs",
 ]
 ```
@@ -153,8 +153,8 @@ If you'd like to automatically create a writable directory if it doesn't already
 `make_writable` behaves the same, but will create the directory before starting the sandbox.
 
 ```toml
-[pkg.foo.test]
-sandbox.make_writable = [
+[pkg.foo]
+test.sandbox.make_writable = [
     "test_outputs",
 ]
 ```

src/config_editor.rs

@@ -164,7 +164,16 @@ impl ConfigEditor {
     }
 
     fn pkg_table(&mut self, perm_sel: &PermSel) -> Result<&mut toml_edit::Table> {
-        self.table(pkg_path(perm_sel))
+        let path = pkg_path(perm_sel);
+        let mut table = self.table(path.clone().take(2))?;
+        for part in path.skip(2) {
+            table = table
+                .entry(part)
+                .or_insert_with(create_dotted_table)
+                .as_table_mut()
+                .ok_or_else(|| anyhow!("[pkg.{perm_sel}] should be a table"))?;
+        }
+        Ok(table)
     }
 
     fn opt_pkg_table(&mut self, perm_sel: &PermSel) -> Result<Option<&mut toml_edit::Table>> {
@@ -394,6 +403,12 @@ fn create_implicit_table() -> Item {
     Item::Table(table)
 }
 
+fn create_dotted_table() -> Item {
+    let mut table = toml_edit::Table::new();
+    table.set_dotted(true);
+    Item::Table(table)
+}
+
 struct CreateCustomConfig;
 
 impl Edit for CreateCustomConfig {
@@ -1110,8 +1125,8 @@ mod tests {
             &disallowed_api(pkg_id("crab1"), PermissionScope::Build, "fs"),
             0,
             indoc! {r#"
-                [pkg.crab1.build]
-                allow_apis = [
+                [pkg.crab1]
+                build.allow_apis = [
                     "fs",
                 ]
             "#,
@@ -1160,8 +1175,8 @@ mod tests {
             &problem,
             1,
             indoc! {r#"
-                [pkg.crab1.build]
-                allow_build_instructions = [
+                [pkg.crab1]
+                build.allow_build_instructions = [
                     "cargo:rustc-env=SOME_VAR=*",
                 ]
             "#,