Add support for turning mdast to hast

1 files changed, 3 insertions, 245 deletions

diff --git a/tests/test_utils/mod.rs b/tests/test_utils/mod.rs
index 10b9643..111118f 100644
--- a/tests/test_utils/mod.rs
+++ b/tests/test_utils/mod.rs
@@ -1,245 +1,3 @@
-extern crate micromark;
-extern crate swc_common;
-extern crate swc_ecma_ast;
-extern crate swc_ecma_parser;
-use micromark::{MdxExpressionKind, MdxSignal};
-use swc_common::{source_map::Pos, BytePos, FileName, SourceFile, Spanned};
-use swc_ecma_ast::{EsVersion, Expr, Module};
-use swc_ecma_parser::{
-    error::Error as SwcError, parse_file_as_expr, parse_file_as_module, EsConfig, Syntax,
-};
-
-/// Parse ESM in MDX with SWC.
-pub fn parse_esm(value: &str) -> MdxSignal {
-    let (file, syntax, version) = create_config(value.to_string());
-    let mut errors = vec![];
-    let result = parse_file_as_module(&file, syntax, version, None, &mut errors);
-
-    match result {
-        Err(error) => swc_error_to_signal(&error, value.len(), 0, "esm"),
-        Ok(tree) => {
-            if errors.is_empty() {
-                check_esm_ast(tree)
-            } else {
-                if errors.len() > 1 {
-                    println!("parse_esm: todo: multiple errors? {:?}", errors);
-                }
-                swc_error_to_signal(&errors[0], value.len(), 0, "esm")
-            }
-        }
-    }
-}
-
-/// Parse expressions in MDX with SWC.
-pub fn parse_expression(value: &str, kind: MdxExpressionKind) -> MdxSignal {
-    // Empty expressions are OK.
-    if matches!(kind, MdxExpressionKind::Expression)
-        && matches!(whitespace_and_comments(0, value), MdxSignal::Ok)
-    {
-        return MdxSignal::Ok;
-    }
-
-    // For attribute expression, a spread is needed, for which we have to prefix
-    // and suffix the input.
-    // See `check_expression_ast` for how the AST is verified.
-    let (prefix, suffix) = if matches!(kind, MdxExpressionKind::AttributeExpression) {
-        ("({", "})")
-    } else {
-        ("", "")
-    };
-
-    let (file, syntax, version) = create_config(format!("{}{}{}", prefix, value, suffix));
-    let mut errors = vec![];
-    let result = parse_file_as_expr(&file, syntax, version, None, &mut errors);
-
-    match result {
-        Err(error) => swc_error_to_signal(&error, value.len(), prefix.len(), "expression"),
-        Ok(tree) => {
-            if errors.is_empty() {
-                let place = fix_swc_position(tree.span().hi.to_usize(), prefix.len());
-                let result = check_expression_ast(tree, kind);
-                if matches!(result, MdxSignal::Ok) {
-                    whitespace_and_comments(place, value)
-                } else {
-                    result
-                }
-            } else {
-                if errors.len() > 1 {
-                    unreachable!("parse_expression: todo: multiple errors? {:?}", errors);
-                }
-                swc_error_to_signal(&errors[0], value.len(), prefix.len(), "expression")
-            }
-        }
-    }
-}
-
-/// Check that the resulting AST of ESM is OK.
-///
-/// This checks that only module declarations (import/exports) are used, not
-/// statements.
-fn check_esm_ast(tree: Module) -> MdxSignal {
-    let mut index = 0;
-    while index < tree.body.len() {
-        let node = &tree.body[index];
-
-        if !node.is_module_decl() {
-            let place = fix_swc_position(node.span().hi.to_usize(), 0);
-            return MdxSignal::Error(
-                "Unexpected statement in code: only import/exports are supported".to_string(),
-                place,
-            );
-        }
-
-        index += 1;
-    }
-
-    MdxSignal::Ok
-}
-
-/// Check that the resulting AST of an expressions is OK.
-///
-/// This checks that attribute expressions are the expected spread.
-fn check_expression_ast(tree: Box<Expr>, kind: MdxExpressionKind) -> MdxSignal {
-    if matches!(kind, MdxExpressionKind::AttributeExpression)
-        && tree
-            .unwrap_parens()
-            .as_object()
-            .and_then(|object| {
-                if object.props.len() == 1 {
-                    object.props[0].as_spread()
-                } else {
-                    None
-                }
-            })
-            .is_none()
-    {
-        MdxSignal::Error(
-            "Expected a single spread value, such as `...x`".to_string(),
-            0,
-        )
-    } else {
-        MdxSignal::Ok
-    }
-}
-
-/// Turn an SWC error into an `MdxSignal`.
-///
-/// * If the error happens at `value_len`, yields `MdxSignal::Eof`
-/// * Else, yields `MdxSignal::Error`.
-fn swc_error_to_signal(
-    error: &SwcError,
-    value_len: usize,
-    prefix_len: usize,
-    name: &str,
-) -> MdxSignal {
-    let message = error.kind().msg().to_string();
-    let place = fix_swc_position(error.span().hi.to_usize(), prefix_len);
-    let message = format!("Could not parse {} with swc: {}", name, message);
-
-    if place >= value_len {
-        MdxSignal::Eof(message)
-    } else {
-        MdxSignal::Error(message, place)
-    }
-}
-
-/// Move past JavaScript whitespace (well, actually ASCII whitespace) and
-/// comments.
-///
-/// This is needed because for expressions, we use an API that parses up to
-/// a valid expression, but there may be more expressions after it, which we
-/// don’t alow.
-fn whitespace_and_comments(mut index: usize, value: &str) -> MdxSignal {
-    let bytes = value.as_bytes();
-    let len = bytes.len();
-    let mut in_multiline = false;
-    let mut in_line = false;
-
-    while index < len {
-        // In a multiline comment: `/* a */`.
-        if in_multiline {
-            if index + 1 < len && bytes[index] == b'*' && bytes[index + 1] == b'/' {
-                index += 1;
-                in_multiline = false;
-            }
-        }
-        // In a line comment: `// a`.
-        else if in_line {
-            if index + 1 < len && bytes[index] == b'\r' && bytes[index + 1] == b'\n' {
-                index += 1;
-                in_line = false;
-            } else if bytes[index] == b'\r' || bytes[index] == b'\n' {
-                in_line = false;
-            }
-        }
-        // Not in a comment, opening a multiline comment: `/* a */`.
-        else if index + 1 < len && bytes[index] == b'/' && bytes[index + 1] == b'*' {
-            index += 1;
-            in_multiline = true;
-        }
-        // Not in a comment, opening a line comment: `// a`.
-        else if index + 1 < len && bytes[index] == b'/' && bytes[index + 1] == b'/' {
-            index += 1;
-            in_line = true;
-        }
-        // Outside comment, whitespace.
-        else if bytes[index].is_ascii_whitespace() {
-            // Fine!
-        }
-        // Outside comment, not whitespace.
-        else {
-            return MdxSignal::Error(
-                "Could not parse expression with swc: Unexpected content after expression"
-                    .to_string(),
-                index,
-            );
-        }
-
-        index += 1;
-    }
-
-    if in_multiline {
-        MdxSignal::Error(
-            "Could not parse expression with swc: Unexpected unclosed multiline comment, expected closing: `*/`".to_string(),
-            index,
-        )
-    } else if in_line {
-        // EOF instead of EOL is specifically not allowed, because that would
-        // mean the closing brace is on the commented-out line
-        MdxSignal::Error(
-            "Could not parse expression with swc: Unexpected unclosed line comment, expected line ending: `\\n`".to_string(),
-            index,
-        )
-    } else {
-        MdxSignal::Ok
-    }
-}
-
-/// Create configuration for SWC, shared between ESM and expressions.
-///
-/// This enables modern JavaScript (ES2022) + JSX.
-fn create_config(source: String) -> (SourceFile, Syntax, EsVersion) {
-    (
-        // File.
-        SourceFile::new(
-            FileName::Anon,
-            false,
-            FileName::Anon,
-            source,
-            BytePos::from_usize(1),
-        ),
-        // Syntax.
-        Syntax::Es(EsConfig {
-            jsx: true,
-            ..EsConfig::default()
-        }),
-        // Version.
-        EsVersion::Es2022,
-    )
-}
-
-/// Turn an SWC byte position from a resulting AST to an offset in the original
-/// input string.
-fn fix_swc_position(index: usize, prefix_len: usize) -> usize {
-    index - 1 - prefix_len
-}
+pub mod hast;
+pub mod swc;
+pub mod to_hast;