Add support for parsing MDX ESM, expressions

This commit adds support for hooks that lets a user integrate another
parser with `micromark-rs`, to parse ESM and expressions according to
a particular grammar (such as a programming language, typically
JavaScript).

For an example integrating with SWC, see `tests/test_utils/mod.rs`.

The integration occurs with two functions passed in `options`:
`mdx_expression_parse` and `mdx_esm_parse`.
The can signal back to micromark when they are successful,
whether there is an error at the end (in which case micromark will
try to parse more), or whether there is a syntax error (in which case
micromark will crash).

1 files changed, 208 insertions, 214 deletions

diff --git a/tests/mdx_expression_text.rs b/tests/mdx_expression_text.rs
index b42faf2..3a48965 100644
--- a/tests/mdx_expression_text.rs
+++ b/tests/mdx_expression_text.rs
@@ -1,147 +1,144 @@
 extern crate micromark;
+mod test_utils;
 use micromark::{micromark_with_options, Constructs, Options};
 use pretty_assertions::assert_eq;
+use test_utils::{parse_esm, parse_expression};
 
-// To do: swc.
-// #[test]
-// fn mdx_expression_text_gnostic_core() -> Result<(), String> {
-//     assert_eq!(
-//         micromark_with_options("a {} b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support an empty expression (1)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a { \t\r\n} b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support an empty expression (2)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {/**/} b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support a multiline comment (1)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {  /*\n*/\t} b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support a multiline comment (2)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {/*b*//*c*/} d", &swc)?,
-//         "<p>a  d</p>",
-//         "should support a multiline comment (3)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {b/*c*/} d", &swc)?,
-//         "<p>a  d</p>",
-//         "should support a multiline comment (4)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {/*b*/c} d", &swc)?,
-//         "<p>a  d</p>",
-//         "should support a multiline comment (4)"
-//     );
-
-//     //   To do: errors.
-//     //   t.throws(
-//     //     () => {
-//     //       micromark_with_options("a {//} b", &swc);
-//     //     },
-//     //     /Could not parse expression with swc: Unexpected token/,
-//     //     "should crash on an incorrect line comment (1)"
-//     //   );
-
-//     //   To do: errors.
-//     //   t.throws(
-//     //     () => {
-//     //       micromark_with_options("a { // b } c", &swc);
-//     //     },
-//     //     /Could not parse expression with swc: Unexpected token/,
-//     //     "should crash on an incorrect line comment (2)"
-//     //   );
-
-//     assert_eq!(
-//         micromark_with_options("a {//\n} b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support a line comment followed by a line ending"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {// b\nd} d", &swc)?,
-//         "<p>a  d</p>",
-//         "should support a line comment followed by a line ending and an expression"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {b// c\n} d", &swc)?,
-//         "<p>a  d</p>",
-//         "should support an expression followed by a line comment and a line ending"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {/*b*/ // c\n} d", &swc)?,
-//         "<p>a  d</p>",
-//         "should support comments (1)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {b.c} d", &swc)?,
-//         "<p>a  d</p>",
-//         "should support expression statements (1)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {1 + 1} b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support expression statements (2)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a {function () {}} b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support expression statements (3)"
-//     );
-
-//     //   To do: errors.
-//     //   t.throws(
-//     //     () => {
-//     //       micromark_with_options("a {var b = \"c\"} d", &swc);
-//     //     },
-//     //     /Could not parse expression with swc: Unexpected token/,
-//     //     "should crash on non-expressions"
-//     //   );
-
-//     assert_eq!(
-//         micromark_with_options("> a {\n> b} c", &swc)?,
-//         "<blockquote>\n<p>a  c</p>\n</blockquote>",
-//         "should support expressions in containers"
-//     );
-
-//     //   To do: errors.
-//     //   t.throws(
-//     //     () => {
-//     //       micromark_with_options("> a {\n> b<} c", &swc);
-//     //     },
-//     //     /Could not parse expression with swc: Unexpected token/,
-//     //     "should crash on incorrect expressions in containers (1)"
-//     //   );
-
-//     //   To do: errors.
-//     //   t.throws(
-//     //     () => {
-//     //       micromark_with_options("> a {\n> b\n> c} d", &swc);
-//     //     },
-//     //     /Could not parse expression with swc: Unexpected content after expression/,
-//     //     "should crash on incorrect expressions in containers (2)"
-//     //   );
-
-//     Ok(())
-// }
+#[test]
+fn mdx_expression_text_gnostic_core() -> Result<(), String> {
+    let swc = Options {
+        constructs: Constructs::mdx(),
+        mdx_esm_parse: Some(Box::new(parse_esm)),
+        mdx_expression_parse: Some(Box::new(parse_expression)),
+        ..Options::default()
+    };
+
+    assert_eq!(
+        micromark_with_options("a {} b", &swc)?,
+        "<p>a  b</p>",
+        "should support an empty expression (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a { \t\r\n} b", &swc)?,
+        "<p>a  b</p>",
+        "should support an empty expression (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {/**/} b", &swc)?,
+        "<p>a  b</p>",
+        "should support a multiline comment (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {  /*\n*/\t} b", &swc)?,
+        "<p>a  b</p>",
+        "should support a multiline comment (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {/*b*//*c*/} d", &swc)?,
+        "<p>a  d</p>",
+        "should support a multiline comment (3)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {b/*c*/} d", &swc)?,
+        "<p>a  d</p>",
+        "should support a multiline comment (4)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {/*b*/c} d", &swc)?,
+        "<p>a  d</p>",
+        "should support a multiline comment (4)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {//} b", &swc).err().unwrap(),
+        "1:4: Could not parse expression with swc: Unexpected eof",
+        "should crash on an incorrect line comment (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a { // b } c", &swc).err().unwrap(),
+        "1:4: Could not parse expression with swc: Unexpected eof",
+        "should crash on an incorrect line comment (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {//\n} b", &swc)?,
+        "<p>a  b</p>",
+        "should support a line comment followed by a line ending"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {// b\nd} d", &swc)?,
+        "<p>a  d</p>",
+        "should support a line comment followed by a line ending and an expression"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {b// c\n} d", &swc)?,
+        "<p>a  d</p>",
+        "should support an expression followed by a line comment and a line ending"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {/*b*/ // c\n} d", &swc)?,
+        "<p>a  d</p>",
+        "should support comments (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {b.c} d", &swc)?,
+        "<p>a  d</p>",
+        "should support expression statements (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {1 + 1} b", &swc)?,
+        "<p>a  b</p>",
+        "should support expression statements (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {function () {}} b", &swc)?,
+        "<p>a  b</p>",
+        "should support expression statements (3)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {var b = \"c\"} d", &swc).err().unwrap(),
+        "1:7: Could not parse expression with swc: Unexpected token `var`. Expected this, import, async, function, [ for array literal, { for object literal, @ for decorator, function, class, null, true, false, number, bigint, string, regexp, ` for template literal, (, or an identifier",
+        "should crash on non-expressions"
+    );
+
+    assert_eq!(
+        micromark_with_options("> a {\n> b} c", &swc)?,
+        "<blockquote>\n<p>a  c</p>\n</blockquote>",
+        "should support expressions in containers"
+    );
+
+    assert_eq!(
+        micromark_with_options("> a {\n> b<} c", &swc)
+            .err()
+            .unwrap(),
+        "2:8: Could not parse expression with swc: Unexpected eof",
+        "should crash on incorrect expressions in containers (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("> a {\n> b\n> c} d", &swc)
+            .err()
+            .unwrap(),
+        "3:3: Could not parse expression with swc: Unexpected content after expression",
+        "should crash on incorrect expressions in containers (2)"
+    );
+
+    Ok(())
+}
 
 #[test]
 fn mdx_expression_text_agnostic() -> Result<(), String> {
@@ -197,77 +194,74 @@ fn mdx_expression_text_agnostic() -> Result<(), String> {
     Ok(())
 }
 
-// // To do: swc.
-// #[test]
-// fn mdx_expression_text_gnostic() -> Result<(), String> {
-//     assert_eq!(
-//         micromark_with_options("a {b} c", &swc)?,
-//         "<p>a  c</p>",
-//         "should support an expression"
-//     );
-
-//     //   To do: errors.
-//     // t.throws(
-//     //     () => {
-//     //     micromark_with_options("a {??} b", &swc);
-//     //     },
-//     //     /Could not parse expression with swc: Unexpected token/,
-//     //     "should crash on an incorrect expression"
-//     // );
-
-//     assert_eq!(
-//         micromark_with_options("a {} b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support an empty expression"
-//     );
-
-//     //   To do: errors.
-//     // t.throws(
-//     //     () => {
-//     //     micromark_with_options("a {b c", &swc);
-//     //     },
-//     //     /Unexpected end of file in expression, expected a corresponding closing brace for `{`/,
-//     //     "should crash if no closing brace is found (1)"
-//     // );
-
-//     //   To do: errors.
-//     // t.throws(
-//     //     () => {
-//     //     micromark_with_options("a {b { c } d", &swc);
-//     //     },
-//     //     /Could not parse expression with swc: Unexpected content after expression/,
-//     //     "should crash if no closing brace is found (2)"
-//     // );
-
-//     assert_eq!(
-//         micromark_with_options("a {\n} b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support a line ending in an expression"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a } b", &swc)?,
-//         "<p>a } b</p>",
-//         "should support just a closing brace"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("{ a } b", &swc)?,
-//         "<p> b</p>",
-//         "should support expressions as the first thing when following by other things"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a { /* { */ } b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support an unbalanced opening brace (if JS permits)"
-//     );
-
-//     assert_eq!(
-//         micromark_with_options("a { /* } */ } b", &swc)?,
-//         "<p>a  b</p>",
-//         "should support an unbalanced closing brace (if JS permits)"
-//     );
-
-//     Ok(())
-// }
+#[test]
+fn mdx_expression_text_gnostic() -> Result<(), String> {
+    let swc = Options {
+        constructs: Constructs::mdx(),
+        mdx_esm_parse: Some(Box::new(parse_esm)),
+        mdx_expression_parse: Some(Box::new(parse_expression)),
+        ..Options::default()
+    };
+
+    assert_eq!(
+        micromark_with_options("a {b} c", &swc)?,
+        "<p>a  c</p>",
+        "should support an expression"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {??} b", &swc).err().unwrap(),
+        "1:9: Could not parse expression with swc: Unexpected eof",
+        "should crash on an incorrect expression"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {} b", &swc)?,
+        "<p>a  b</p>",
+        "should support an empty expression"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {b c", &swc).err().unwrap(),
+        "1:7: Unexpected end of file in expression, expected a corresponding closing brace for `{`",
+        "should crash if no closing brace is found (1)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {b { c } d", &swc).err().unwrap(),
+        "1:6: Could not parse expression with swc: Unexpected content after expression",
+        "should crash if no closing brace is found (2)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a {\n} b", &swc)?,
+        "<p>a  b</p>",
+        "should support a line ending in an expression"
+    );
+
+    assert_eq!(
+        micromark_with_options("a } b", &swc)?,
+        "<p>a } b</p>",
+        "should support just a closing brace"
+    );
+
+    assert_eq!(
+        micromark_with_options("{ a } b", &swc)?,
+        "<p> b</p>",
+        "should support expressions as the first thing when following by other things"
+    );
+
+    assert_eq!(
+        micromark_with_options("a { /* { */ } b", &swc)?,
+        "<p>a  b</p>",
+        "should support an unbalanced opening brace (if JS permits)"
+    );
+
+    assert_eq!(
+        micromark_with_options("a { /* } */ } b", &swc)?,
+        "<p>a  b</p>",
+        "should support an unbalanced closing brace (if JS permits)"
+    );
+
+    Ok(())
+}