rewriteDefault() — vue Function Reference

Architecture documentation for the rewriteDefault() function in rewriteDefault.ts from the vue codebase.

Function typescript CompilerSFC ScriptCompiler calls 2 called by 1

Entity Profile

CompilerSFC→ ScriptCompiler→ rewriteDefault() — vue Function Reference

Dependency Diagram

graph TD
  7e881ac8_aa91_c10a_bd6a_7071900a38fa["rewriteDefault()"]
  af57cd20_c4ce_0877_c02c_52056ca04d4a["compileScript()"]
  af57cd20_c4ce_0877_c02c_52056ca04d4a -->|calls| 7e881ac8_aa91_c10a_bd6a_7071900a38fa
  3b943cf7_6d62_ecf7_226d_a35892b66468["hasDefaultExport()"]
  7e881ac8_aa91_c10a_bd6a_7071900a38fa -->|calls| 3b943cf7_6d62_ecf7_226d_a35892b66468
  3be7e92f_b701_5270_8d86_c8014f4ae977["specifierEnd()"]
  7e881ac8_aa91_c10a_bd6a_7071900a38fa -->|calls| 3be7e92f_b701_5270_8d86_c8014f4ae977
  style 7e881ac8_aa91_c10a_bd6a_7071900a38fa fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/compiler-sfc/src/rewriteDefault.ts lines 13–95

export function rewriteDefault(
  input: string,
  as: string,
  parserPlugins?: ParserPlugin[]
): string {
  if (!hasDefaultExport(input)) {
    return input + `\nconst ${as} = {}`
  }

  let replaced: string | undefined

  const classMatch = input.match(exportDefaultClassRE)
  if (classMatch) {
    replaced =
      input.replace(exportDefaultClassRE, '$1class $2') +
      `\nconst ${as} = ${classMatch[2]}`
  } else {
    replaced = input.replace(defaultExportRE, `$1const ${as} =`)
  }
  if (!hasDefaultExport(replaced)) {
    return replaced
  }

  // if the script somehow still contains `default export`, it probably has
  // multi-line comments or template strings. fallback to a full parse.
  const s = new MagicString(input)
  const ast = parse(input, {
    sourceType: 'module',
    plugins: parserPlugins
  }).program.body
  ast.forEach(node => {
    if (node.type === 'ExportDefaultDeclaration') {
      if (node.declaration.type === 'ClassDeclaration' && node.declaration.id) {
        let start: number =
          node.declaration.decorators && node.declaration.decorators.length > 0
            ? node.declaration.decorators[
                node.declaration.decorators.length - 1
              ].end!
            : node.start!
        s.overwrite(start, node.declaration.id.start!, ` class `)
        s.append(`\nconst ${as} = ${node.declaration.id.name}`)
      } else {
        s.overwrite(node.start!, node.declaration.start!, `const ${as} = `)
      }
    }
    if (node.type === 'ExportNamedDeclaration') {
      for (const specifier of node.specifiers) {
        if (
          specifier.type === 'ExportSpecifier' &&
          specifier.exported.type === 'Identifier' &&
          specifier.exported.name === 'default'
        ) {
          if (node.source) {
            if (specifier.local.name === 'default') {
              const end = specifierEnd(input, specifier.local.end!, node.end)
              s.prepend(
                `import { default as __VUE_DEFAULT__ } from '${node.source.value}'\n`
              )
              s.overwrite(specifier.start!, end, ``)
              s.append(`\nconst ${as} = __VUE_DEFAULT__`)
              continue
            } else {
              const end = specifierEnd(input, specifier.exported.end!, node.end)
              s.prepend(
                `import { ${input.slice(
                  specifier.local.start!,
                  specifier.local.end!
                )} } from '${node.source.value}'\n`
              )
              s.overwrite(specifier.start!, end, ``)
              s.append(`\nconst ${as} = ${specifier.local.name}`)
              continue
            }
          }
          const end = specifierEnd(input, specifier.end!, node.end)
          s.overwrite(specifier.start!, end, ``)
          s.append(`\nconst ${as} = ${specifier.local.name}`)
        }
      }
    }
  })
  return s.toString()
}