1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164

use std::iter;

use swc_common::{util::take::Take, DUMMY_SP};
use swc_ecma_ast::*;
use swc_ecma_visit::{noop_fold_type, noop_visit_mut_type, Fold, FoldWith, VisitMut, VisitMutWith};

use crate::{prepend_stmts, ExprFactory};

pub fn inject_after_super(c: &mut Constructor, mut exprs: Vec<Box<Expr>>) {
    // Allow using super multiple time
    let mut folder = Injector {
        exprs: &mut exprs,
        injected: false,
    };

    c.body = std::mem::take(&mut c.body).fold_with(&mut folder);
    if !folder.injected {
        if c.body.is_none() {
            c.body = Some(BlockStmt {
                span: DUMMY_SP,
                stmts: vec![],
            });
        }
        // there was no super() call
        prepend_stmts(
            &mut c.body.as_mut().unwrap().stmts,
            exprs.into_iter().map(|v| v.into_stmt()),
        );
    }
}

struct Injector<'a> {
    injected: bool,
    exprs: &'a mut Vec<Box<Expr>>,
}

impl<'a> Fold for Injector<'a> {
    noop_fold_type!();

    fn fold_class(&mut self, c: Class) -> Class {
        c
    }

    fn fold_constructor(&mut self, n: Constructor) -> Constructor {
        n
    }

    fn fold_function(&mut self, n: Function) -> Function {
        n
    }

    fn fold_stmts(&mut self, stmts: Vec<Stmt>) -> Vec<Stmt> {
        if self.exprs.is_empty() {
            return stmts;
        }

        let mut buf = Vec::with_capacity(stmts.len() + 8);

        stmts.into_iter().for_each(|stmt| {
            if let Stmt::Expr(ExprStmt { ref expr, .. }) = stmt {
                if let Expr::Call(CallExpr {
                    callee: Callee::Super(..),
                    ..
                }) = &**expr
                {
                    self.injected = true;
                    buf.push(stmt);
                    buf.extend(self.exprs.clone().into_iter().map(|v| v.into_stmt()));
                    return;
                }
            }

            let mut folder = Injector {
                injected: false,
                exprs: self.exprs,
            };
            let mut stmt = stmt.fold_children_with(&mut folder);
            self.injected |= folder.injected;
            if folder.injected {
                buf.push(stmt);
            } else {
                let mut folder = ExprInjector {
                    injected: false,
                    exprs: self.exprs,
                    injected_tmp: None,
                };
                stmt.visit_mut_with(&mut folder);

                self.injected |= folder.injected;

                buf.extend(folder.injected_tmp.map(|ident| {
                    Stmt::Decl(Decl::Var(Box::new(VarDecl {
                        span: DUMMY_SP,
                        kind: VarDeclKind::Var,
                        decls: vec![VarDeclarator {
                            span: DUMMY_SP,
                            name: Pat::Ident(ident.into()),
                            init: None,
                            definite: false,
                        }],
                        declare: false,
                    })))
                }));
                buf.push(stmt);
            }
        });

        buf
    }
}

/// Handles code like `foo(super())`
struct ExprInjector<'a> {
    injected: bool,
    exprs: &'a mut Vec<Box<Expr>>,
    injected_tmp: Option<Ident>,
}

impl VisitMut for ExprInjector<'_> {
    noop_visit_mut_type!();

    fn visit_mut_class(&mut self, c: &mut Class) {
        c.super_class.visit_mut_with(self);
    }

    fn visit_mut_constructor(&mut self, _: &mut Constructor) {}

    fn visit_mut_expr(&mut self, expr: &mut Expr) {
        expr.visit_mut_children_with(self);

        if let Expr::Call(CallExpr {
            callee: Callee::Super(..),
            ..
        }) = expr
        {
            self.injected_tmp = Some(
                self.injected_tmp
                    .take()
                    .unwrap_or_else(|| private_ident!("_temp")),
            );
            self.injected = true;
            let e = expr.take();

            *expr = Expr::Seq(SeqExpr {
                span: DUMMY_SP,
                exprs: iter::once(Box::new(Expr::Assign(AssignExpr {
                    span: DUMMY_SP,
                    left: PatOrExpr::Pat(Box::new(Pat::Ident(
                        self.injected_tmp.as_ref().cloned().unwrap().into(),
                    ))),
                    op: op!("="),
                    right: Box::new(e),
                })))
                .chain(self.exprs.clone())
                .chain(iter::once(Box::new(Expr::Ident(
                    self.injected_tmp.as_ref().cloned().unwrap(),
                ))))
                .collect(),
            })
        }
    }

    fn visit_mut_function(&mut self, _: &mut Function) {}
}