TypeScript babel-types.isBlockStatement函數代碼示例

  /**
   * TS 編譯器會把 class property 移到構造器，
   * 而小程序要求 `config` 和所有函數在初始化(after new Class)之後就收集到所有的函數和 config 信息，
   * 所以當如構造器裏有 this.func = () => {...} 的形式，就給他轉換成普通的 classProperty function
   * 如果有 config 就給他還原
   */
function resetTSClassProperty (body: (t.ClassMethod | t.ClassProperty)[]) {
  for (const method of body) {
    if (t.isClassMethod(method) && method.kind === 'constructor') {
      if (t.isBlockStatement(method.body)) {
        method.body.body = method.body.body.filter(statement => {
          if (t.isExpressionStatement(statement) && t.isAssignmentExpression(statement.expression)) {
            const expr = statement.expression
            const { left, right } = expr
            if (
              t.isMemberExpression(left) &&
              t.isThisExpression(left.object) &&
              t.isIdentifier(left.property)
            ) {
              if (
                (t.isArrowFunctionExpression(right) || t.isFunctionExpression(right))
                ||
                (left.property.name === 'config' && t.isObjectExpression(right))
              ) {
                const classProp = t.classProperty(left.property, right)
                body.push(classProp)
                handleThirdPartyComponent(classProp)
                return false
              }
            }
          }
          return true
        })
      }
    }
  }
}

export function generateAnonymousState (
  scope: Scope,
  expression: NodePath<t.Expression>,
  refIds: Set<t.Identifier>,
  isLogical?: boolean
) {
  let variableName = `anonymousState_${scope.generateUid()}`
  let statementParent = expression.getStatementParent()
  if (!statementParent) {
    throw codeFrameError(expression.node.loc, '無法生成匿名 State，嘗試先把值賦到一個變量上再把變量調換。')
  }
  const jsx = isLogical ? expression : expression.findParent(p => p.isJSXElement())
  const callExpr = jsx.findParent(p => p.isCallExpression() && isArrayMapCallExpression(p)) as NodePath<t.CallExpression>
  const ifExpr = jsx.findParent(p => p.isIfStatement())
  const blockStatement = jsx.findParent(p => p.isBlockStatement() && p.parentPath === ifExpr) as NodePath<t.BlockStatement>
  const expr = setParentCondition(jsx, cloneDeep(expression.node))
  if (!callExpr) {
    refIds.add(t.identifier(variableName))
    statementParent.insertBefore(
      buildConstVariableDeclaration(variableName, expr)
    )
    if (blockStatement && blockStatement.isBlockStatement()) {
      blockStatement.traverse({
        VariableDeclarator: (p) => {
          const { id, init } = p.node
          if (t.isIdentifier(id)) {
            const newId = scope.generateDeclaredUidIdentifier('$' + id.name)
            refIds.forEach((refId) => {
              if (refId.name === variableName && !variableName.startsWith('_$')) {
                refIds.delete(refId)
              }
            })
            variableName = newId.name
            refIds.add(t.identifier(variableName))
            blockStatement.scope.rename(id.name, newId.name)
            p.parentPath.replaceWith(
              template('ID = INIT;')({ ID: newId, INIT: init })
            )
          }
        }
      })
    }
  } else {
    variableName = `${LOOP_STATE}_${callExpr.scope.generateUid()}`
    const func = callExpr.node.arguments[0]
    if (t.isArrowFunctionExpression(func)) {
      if (!t.isBlockStatement(func.body)) {
        func.body = t.blockStatement([
          buildConstVariableDeclaration(variableName, expr),
          t.returnStatement(func.body)
        ])
      } else {
        func.body.body.splice(func.body.body.length - 1, 0, buildConstVariableDeclaration(variableName, expr))
      }
    }
  }
  const id = t.identifier(variableName)
  expression.replaceWith(id)
  return id
}

export function generateAnonymousState (
  scope: Scope,
  expression: NodePath<t.Expression>,
  refIds: Set<t.Identifier>,
  isLogical?: boolean
) {
  let variableName = `anonymousState_${scope.generateUid()}`
  let statementParent = expression.getStatementParent()
  if (!statementParent) {
    throw codeFrameError(expression.node.loc, '無法生成匿名 State，嘗試先把值賦到一個變量上再把變量調換。')
  }
  const jsx = isLogical ? expression : expression.findParent(p => p.isJSXElement())
  const callExpr = jsx.findParent(p => p.isCallExpression() && isArrayMapCallExpression(p)) as NodePath<t.CallExpression>
  const conditionExpr = jsx.findParent(p => p.isConditionalExpression())
  const logicExpr = jsx.findParent(p => p.isLogicalExpression({ operator: '&&' }))
  let expr = cloneDeep(expression.node)
  if (conditionExpr && conditionExpr.isConditionalExpression()) {
    const consequent = conditionExpr.get('consequent')
    if (consequent === jsx || jsx.findParent(p => p === consequent)) {
      expr = t.conditionalExpression(conditionExpr.get('test').node as any, expr, t.nullLiteral())
    }
  }
  if (logicExpr && logicExpr.isLogicalExpression({ operator: '&&' })) {
    const consequent = logicExpr.get('right')
    if (consequent === jsx || jsx.findParent(p => p === consequent)) {
      expr = t.conditionalExpression(logicExpr.get('left').node as any, expr, t.nullLiteral())
    }
  }
  if (!callExpr) {
    refIds.add(t.identifier(variableName))
    statementParent.insertBefore(
      buildConstVariableDeclaration(variableName, expr)
    )
  } else {
    variableName = `${LOOP_STATE}_${callExpr.scope.generateUid()}`
    const func = callExpr.node.arguments[0]
    if (t.isArrowFunctionExpression(func)) {
      if (!t.isBlockStatement(func.body)) {
        func.body = t.blockStatement([
          buildConstVariableDeclaration(variableName, expr),
          t.returnStatement(func.body)
        ])
      } else {
        statementParent.insertBefore(
          buildConstVariableDeclaration(variableName, expr)
        )
      }
    }
  }
  expression.replaceWith(
    t.identifier(variableName)
  )
}

export function generateAnonymousState (
  scope: Scope,
  expression: NodePath<t.Expression>,
  refIds: Set<t.Identifier>,
  isLogical?: boolean
) {
  let variableName = `anonymousState_${scope.generateUid()}`
  let statementParent = expression.getStatementParent()
  if (!statementParent) {
    throw codeFrameError(expression.node.loc, '無法生成匿名 State，嘗試先把值賦到一個變量上再把變量調換。')
  }
  const jsx = isLogical ? expression : expression.findParent(p => p.isJSXElement())
  const callExpr = jsx.findParent(p => p.isCallExpression() && isArrayMapCallExpression(p)) as NodePath<t.CallExpression>
  const ifExpr = jsx.findParent(p => p.isIfStatement())
  const blockStatement = jsx.findParent(p => p.isBlockStatement() && p.parentPath === ifExpr) as NodePath<t.BlockStatement>
  const expr = setParentCondition(jsx, cloneDeep(expression.node))
  if (!callExpr) {
    refIds.add(t.identifier(variableName))
    statementParent.insertBefore(
      buildConstVariableDeclaration(variableName, expr)
    )
    if (blockStatement && blockStatement.isBlockStatement()) {
      blockStatement.traverse({
        VariableDeclarator: (path) => {
          const { id, init } = path.node
          const isArrowFunctionInJSX = path.findParent(p => p.isJSXAttribute() ||
            (
              p.isAssignmentExpression() && t.isMemberExpression(p.node.left) && t.isThisExpression(p.node.left.object)
                && t.isIdentifier(p.node.left.property) && p.node.left.property.name.startsWith('')
            )
          )
          if (isArrowFunctionInJSX) {
            return
          }
          if (t.isIdentifier(id) && !id.name.startsWith(LOOP_STATE)) {
            const newId = scope.generateDeclaredUidIdentifier('$' + id.name)
            refIds.forEach((refId) => {
              if (refId.name === variableName && !variableName.startsWith('_$')) {
                refIds.delete(refId)
              }
            })
            variableName = newId.name
            if (Adapter.type === Adapters.quickapp && variableName.startsWith('_$')) {
              const newVarName = variableName.slice(2)
              scope.rename(variableName, newVarName)
              variableName = newVarName
            }
            refIds.add(t.identifier(variableName))
            blockStatement.scope.rename(id.name, newId.name)
            path.parentPath.replaceWith(
              template('ID = INIT;')({ ID: newId, INIT: init })
            )
          }
        }
      })
    }
  } else {
    variableName = `${LOOP_STATE}_${callExpr.scope.generateUid()}`
    const func = callExpr.node.arguments[0]
    if (t.isArrowFunctionExpression(func)) {
      if (!t.isBlockStatement(func.body)) {
        func.body = t.blockStatement([
          buildConstVariableDeclaration(variableName, expr),
          t.returnStatement(func.body)
        ])
      } else {
        if (ifExpr && ifExpr.isIfStatement() && ifExpr.findParent(p => p === callExpr)) {
          const consequent = ifExpr.get('consequent')
          const test = ifExpr.get('test')
          if (consequent.isBlockStatement()) {
            if (jsx === test || jsx.findParent(p => p === test)) {
              func.body.body.unshift(buildConstVariableDeclaration(variableName, expr))
            } else {
              func.body.body.unshift(t.variableDeclaration('let', [t.variableDeclarator(t.identifier(variableName), t.nullLiteral())]))
              consequent.node.body.push(t.expressionStatement(t.assignmentExpression(
                '=',
                t.identifier(variableName),
                expr
              )))
            }
          } else {
            throw codeFrameError(consequent.node, 'if 表達式的結果必須由一個花括號包裹')
          }
        } else {
          func.body.body.splice(func.body.body.length - 1, 0, buildConstVariableDeclaration(variableName, expr))
        }
      }
    }
  }
  const id = t.identifier(variableName)
  expression.replaceWith(id)
  return id
}

} = () => {
  return {
    visitor: {
      JSXElement (path) {
        const arrowFuncExpr = path.findParent(p => p.isArrowFunctionExpression())
        if (arrowFuncExpr && arrowFuncExpr.isArrowFunctionExpression() && arrowFuncExpr.parentPath.isVariableDeclarator()) {
          const valDecl = arrowFuncExpr.parentPath.parentPath
          if (!valDecl.isVariableDeclaration()) {
            throw codeFrameError(valDecl.node, '函數式組件不能同時定義多個值')
          }
          const id = arrowFuncExpr.parentPath.node.id
          if (!t.isIdentifier(id)) {
            throw codeFrameError(id, '函數式組件隻能使用普通標識符定義')
          }
          if (!initialIsCapital(id.name)) {
            return
          }
          const hasClassDecl = arrowFuncExpr.findParent(p => p.isClassDeclaration())
          if (hasClassDecl) {
            // @TODO: 加上鏈接
            return
          }
          const { body } = arrowFuncExpr.node
          if (t.isBlockStatement(body)) {
            valDecl.replaceWith(t.functionDeclaration(id, arrowFuncExpr.node.params, body))
          } else {
            valDecl.replaceWith(t.functionDeclaration(id, arrowFuncExpr.node.params, t.blockStatement([
              t.returnStatement(body)
            ])))
          }
          return
        }

        const functionDecl = path.findParent(p => p.isFunctionDeclaration())
        if (functionDecl && functionDecl.isFunctionDeclaration()) {
          const hasClassDecl = functionDecl.findParent(p => p.isClassDeclaration())
          if (hasClassDecl) {
            // @TODO: 加上鏈接
            return
          }
          const { id, body, params } = functionDecl.node
          let arg: null | t.LVal = null
          if (params.length > 1) {
            throw codeFrameError(id, '函數式組件的參數最多隻能傳入一個')
          } else if (params.length === 1) {
            arg = params[0]
          }
          const cloneBody = cloneDeep(body)
          if (!initialIsCapital(id.name)) {
            throw codeFrameError(id, `普通函數式組件命名規則請遵守帕斯卡命名法（Pascal Case), 如果是在函數內聲明閉包組件，則需要使用函數表達式的寫法。
形如:
const ${id.name} = ${generate(t.arrowFunctionExpression(params, body)).code}
            `)
          }
          if (arg) {
            if (t.isIdentifier(arg)) {
              cloneBody.body.unshift(buildConstVariableDeclaration(arg.name, t.memberExpression(t.thisExpression(), t.identifier('props'))))
            } else if (t.isObjectPattern(arg)) {
              cloneBody.body.unshift(
                t.variableDeclaration('const', [
                  t.variableDeclarator(arg, t.memberExpression(t.thisExpression(), t.identifier('props')))
                ])
              )
            } else {
              throw codeFrameError(arg, '函數式組件隻支持傳入一個簡單標識符或使用對象結構')
            }
          }
          const classDecl = t.classDeclaration(id, t.memberExpression(t.identifier('Taro'), t.identifier('Component')), t.classBody([
            t.classMethod('method', t.identifier('render'), [], cloneBody)
          ]), [])
          functionDecl.replaceWith(classDecl)
        }
      }
    }
  }
}