TypeScript babel-types.isStringLiteral函数代码示例

 attributes: attributes.reduce((obj, attr) => {
   if (t.isJSXSpreadAttribute(attr)) {
     throw codeFrameError(attr.loc, 'JSX 参数暂不支持 ...spread 表达式')
   }
   const name = attr.name.name === 'className' ? 'class' : attr.name.name
   let value: string | boolean = true
   let attrValue = attr.value
   if (typeof name === 'string') {
     if (t.isStringLiteral(attrValue)) {
       value = attrValue.value
     } else if (t.isJSXExpressionContainer(attrValue)) {
       const isBindEvent =
         name.startsWith('bind') || name.startsWith('catch')
       let { code } = generate(attrValue.expression)
       code = code
         .replace(/(this\.props\.)|(this\.state\.)/, '')
         .replace(/this\./, '')
       value = isBindEvent ? code : `{{${code}}}`
       if (t.isStringLiteral(attrValue.expression)) {
         value = attrValue.expression.value
       }
     }
     if (
       componentSpecialProps &&
       componentSpecialProps.has(name)
     ) {
       obj[name] = value
     } else {
       obj[isDefaultComponent && !name.includes('-') && !name.includes(':') ? kebabCase(name) : name] = value
     }
   }
   return obj
 }, {}),

function getWXS (attrs: t.JSXAttribute[], path: NodePath<t.JSXElement>, imports: Imports[]): WXS {
  let moduleName: string | null = null
  let src: string | null = null

  for (const attr of attrs) {
    if (t.isJSXIdentifier(attr.name)) {
      const attrName = attr.name.name
      const attrValue = attr.value
      let value: string | null = null
      if (attrValue === null) {
        throw new Error('WXS 标签的属性值不得为空')
      }
      if (t.isStringLiteral(attrValue)) {
        value = attrValue.value
      } else if (
        t.isJSXExpressionContainer(attrValue) &&
        t.isStringLiteral(attrValue.expression)
      ) {
        value = attrValue.expression.value
      }
      if (attrName === 'module') {
        moduleName = value
      }
      if (attrName === 'src') {
        src = value
      }
    }
  }

  if (!src) {
    const { children: [ script ] } = path.node
    if (!t.isJSXText(script)) {
      throw new Error('wxs 如果没有 src 属性，标签内部必须有 wxs 代码。')
    }
    src = './wxs__' + moduleName
    imports.push({
      ast: parseCode(script.value),
      name: moduleName as string,
      wxs: true
    })
  }

  if (!moduleName || !src) {
    throw new Error('一个 WXS 需要同时存在两个属性：`wxs`, `src`')
  }

  path.remove()

  return {
    module: moduleName,
    src
  }
}

 attributesTrans = attributes.reduce((obj, attr) => {
   if (t.isJSXSpreadAttribute(attr)) {
     throw codeFrameError(attr.loc, 'JSX 参数暂不支持 ...spread 表达式')
   }
   let name = attr.name.name
   if (DEFAULT_Component_SET.has(componentName)) {
     if (name === 'className') {
       name = 'class'
     }
   }
   let value: string | boolean = true
   let attrValue = attr.value
   if (typeof name === 'string') {
     const isAlipayEvent = Adapter.type === Adapters.alipay && /(^on[A-Z_])|(^catch[A-Z_])/.test(name)
     if (t.isStringLiteral(attrValue)) {
       value = attrValue.value
     } else if (t.isJSXExpressionContainer(attrValue)) {
       let isBindEvent =
         (name.startsWith('bind') && name !== 'bind') || (name.startsWith('catch') && name !== 'catch')
       const code = decodeUnicode(generate(attrValue.expression, {
           quotes: 'single',
           concise: true
         }).code)
         .replace(/"/g, "'")
         .replace(/(this\.props\.)|(this\.state\.)/g, '')
         .replace(/this\./g, '')
       value = isBindEvent || isAlipayEvent ? code : `{{${code}}}`
       if (Adapter.type === Adapters.swan && name === Adapter.for) {
         value = code
       }
       if (t.isStringLiteral(attrValue.expression)) {
         value = attrValue.expression.value
       }
     } else if (attrValue === null && name !== Adapter.else) {
       value = `{{true}}`
     }
     if ((componentName === 'Input' || componentName === 'input') && name === 'maxLength') {
       obj['maxlength'] = value
     } else if (
       componentSpecialProps && componentSpecialProps.has(name) ||
       name.startsWith('__fn_') ||
       isAlipayEvent
     ) {
       obj[name] = value
     } else {
       obj[isDefaultComponent && !name.includes('-') && !name.includes(':') ? kebabCase(name) : name] = value
     }
   }
   if (!isDefaultComponent && !specialComponentName.includes(componentName)) {
     obj[TRIGGER_OBSERER] = '{{ _triggerObserer }}'
   }
   return obj
 }, {})

 .forEach(prop => {
   if (t.isObjectProperty(prop)) {
     let propKey: string | null = null
     if (t.isStringLiteral(prop.key)) {
       propKey = prop.key.value
     }
     if (t.isIdentifier(prop.key)) {
       propKey = prop.key.name
       // propsKeys.push(prop.key.name)
     }
     if (t.isObjectExpression(prop.value) && propKey) {
       for (const p of prop.value.properties) {
         if (t.isObjectProperty(p)) {
           let key: string | null = null
           if (t.isStringLiteral(p.key)) {
             key = p.key.value
           }
           if (t.isIdentifier(p.key)) {
             key = p.key.name
           }
           if (key === 'value') {
             defaultProps.push({
               name: propKey,
               value: p.value
             })
           } else if (key === 'observer') {
             observeProps.push({
               name: propKey,
               observer: p.value
             })
           }
           if (!isValidVarName(propKey)) {
             throw codeFrameError(prop, `${propKey} 不是一个合法的 JavaScript 变量名`)
           }
         }
         if (t.isObjectMethod(p) && t.isIdentifier(p.key, { name: 'observer' })) {
           observeProps.push({
             name: propKey,
             observer: t.arrowFunctionExpression(p.params, p.body, p.async)
           })
         }
       }
     }
     if (propKey) {
       propsKeys.push(propKey)
     }
   }
 })

 /**
  * Rewrite export declarations source URLs to reference the bundle URL for
  * bundled files.
  */
 private _rewriteExportStatements(baseUrl: ResolvedUrl, node: babel.Node) {
   const this_ = this;
   traverse(node, {
     noScope: true,
     ExportNamedDeclaration: {
       enter(path: NodePath<babel.ExportNamedDeclaration>) {
         const exportNamedDeclaration = path.node;
         if (!exportNamedDeclaration.source ||
             !babel.isStringLiteral(exportNamedDeclaration.source)) {
           // We can't rewrite a source if there isn't one or if it isn't a
           // string literal in the first place.
           return;
         }
         const source = exportNamedDeclaration.source.value as ResolvedUrl;
         const sourceBundle = this_.manifest.getBundleForFile(source);
         // If there is no bundle associated with the export from statement
         // then the URL is not bundled (perhaps it was excluded) so we will
         // just ensure the URL is converted back to a relative URL.
         if (!sourceBundle) {
           exportNamedDeclaration.source.value = ensureLeadingDot(
               this_.bundler.analyzer.urlResolver.relative(baseUrl, source));
           return;
         }
         exportNamedDeclaration.source.value =
             ensureLeadingDot(this_.bundler.analyzer.urlResolver.relative(
                 baseUrl, sourceBundle.url));
       }
     }
   });
 }

 rewriteExportAllToNamedExports(node: babel.Node, analysis: Analysis) {
   traverse(node, {
     noScope: true,
     ExportAllDeclaration: {
       enter(path: NodePath<babel.ExportAllDeclaration>) {
         const exportAllDeclaration = path.node;
         const sourceUrl =
             babel.isStringLiteral(exportAllDeclaration.source) &&
             exportAllDeclaration.source.value;
         if (!sourceUrl) {
           return;
         }
         const sourceDocument = getAnalysisDocument(analysis, sourceUrl);
         const documentExports = sourceDocument.getFeatures({kind: 'export'});
         const specifiers: babel.ExportSpecifier[] = [];
         for (const documentExport of documentExports) {
           for (const exportIdentifier of documentExport.identifiers) {
             const identifierValue = exportIdentifier.valueOf();
             // It does not appear that `export * from` should re-export
             // the default module export of a module.
             if (identifierValue !== 'default') {
               specifiers.push(babel.exportSpecifier(
                   babel.identifier(identifierValue),
                   babel.identifier(identifierValue)));
             }
           }
         }
         const namedExportDeclaration = babel.exportNamedDeclaration(
             undefined, specifiers, babel.stringLiteral(sourceUrl));
         rewriteObject(exportAllDeclaration, namedExportDeclaration);
       }
     }
   });
 }

 getEs6ImportResolutions(document: Document): Map<string, ResolvedUrl> {
   const jsImports = document.getFeatures({
     kind: 'js-import',
     imported: false,
     externalPackages: true,
     excludeBackreferences: true,
   });
   const resolutions = new Map<string, ResolvedUrl>();
   for (const jsImport of jsImports) {
     const node = jsImport.astNode.node;
     if ('source' in node) {
       if (node.source && jsImport.document !== undefined) {
         resolutions.set(node.source.value, jsImport.document.url);
       }
     } else if (
         node.callee && node.callee.type + '' === 'Import' &&
         jsImport.document !== undefined) {
       const source = node.arguments[0];
       if (source) {
         if (babel.isStringLiteral(source)) {
           resolutions.set(source.value, jsImport.document.url);
         }
       }
     }
   }
   return resolutions;
 }

 /**
  * Attempts to reduce the number of distinct import declarations by combining
  * those referencing the same source into the same declaration. Results in
  * deduplication of imports of the same item as well.
  *
  * Before:
  *     import {a} from './module-1.js';
  *     import {b} from './module-1.js';
  *     import {c} from './module-2.js';
  * After:
  *     import {a,b} from './module-1.js';
  *     import {c} from './module-2.js';
  */
 private _deduplicateImportStatements(node: babel.Node) {
   const importDeclarations = new Map<string, babel.ImportDeclaration>();
   traverse(node, {
     noScope: true,
     ImportDeclaration: {
       enter(path: NodePath) {
         const importDeclaration = path.node;
         if (!babel.isImportDeclaration(importDeclaration)) {
           return;
         }
         const source = babel.isStringLiteral(importDeclaration.source) &&
             importDeclaration.source.value;
         if (!source) {
           return;
         }
         const hasNamespaceSpecifier = importDeclaration.specifiers.some(
             (s) => babel.isImportNamespaceSpecifier(s));
         const hasDefaultSpecifier = importDeclaration.specifiers.some(
             (s) => babel.isImportDefaultSpecifier(s));
         if (!importDeclarations.has(source) && !hasNamespaceSpecifier &&
             !hasDefaultSpecifier) {
           importDeclarations.set(source, importDeclaration);
         } else if (importDeclarations.has(source)) {
           const existingDeclaration = importDeclarations.get(source)!;
           for (const specifier of importDeclaration.specifiers) {
             existingDeclaration.specifiers.push(specifier);
           }
           path.remove();
         }
       }
     }
   });
 }

 .forEach(p => {
   const node = p.node
   if (node.name.name === WX_FOR_ITEM) {
     if (!node.value || !t.isStringLiteral(node.value)) {
       throw new Error(WX_FOR_ITEM + ' 的值必须是一个字符串')
     }
     item = node.value
     p.remove()
   }
   if (node.name.name === WX_FOR_INDEX) {
     if (!node.value || !t.isStringLiteral(node.value)) {
       throw new Error(WX_FOR_INDEX + ' 的值必须是一个字符串')
     }
     index = node.value
     p.remove()
   }
 })

  /**
   * Rewrite import declarations source URLs reference the bundle URL for
   * bundled files and import names to correspond to names as exported by
   * bundles.
   */
  private _rewriteImportStatements(baseUrl: ResolvedUrl, node: babel.Node) {
    const this_ = this;
    traverse(node, {
      noScope: true,
      // Dynamic import() syntax doesn't have full type support yet, so we
      // have to use generic `enter` and walk all nodes until that's fixed.
      // TODO(usergenic): Switch this to the `Import: { enter }` style
      // after dynamic imports fully supported.
      enter(path: NodePath) {
        if (path.node.type === 'Import') {
          this_._rewriteDynamicImport(baseUrl, node, path);
        }
      },
    });

    traverse(node, {
      noScope: true,
      ImportDeclaration: {
        enter(path: NodePath) {
          const importDeclaration = path.node as babel.ImportDeclaration;
          if (!babel.isStringLiteral(importDeclaration.source)) {
            // We can't actually handle values which are not string literals, so
            // we'll skip them.
            return;
          }
          const source = importDeclaration.source.value as ResolvedUrl;
          const sourceBundle = this_.manifest.getBundleForFile(source);
          // If there is no import bundle, then this URL is not bundled (maybe
          // excluded or something) so we should just ensure the URL is
          // converted back to a relative URL.
          if (!sourceBundle) {
            importDeclaration.source.value =
                this_.bundler.analyzer.urlResolver.relative(baseUrl, source);
            return;
          }
          for (const specifier of importDeclaration.specifiers) {
            if (babel.isImportSpecifier(specifier)) {
              this_._rewriteImportSpecifierName(
                  specifier, source, sourceBundle);
            }
            if (babel.isImportDefaultSpecifier(specifier)) {
              this_._rewriteImportDefaultSpecifier(
                  specifier, source, sourceBundle);
            }
            if (babel.isImportNamespaceSpecifier(specifier)) {
              this_._rewriteImportNamespaceSpecifier(
                  specifier, source, sourceBundle);
            }
          }
          importDeclaration.source.value =
              ensureLeadingDot(this_.bundler.analyzer.urlResolver.relative(
                  baseUrl, sourceBundle.url));
        }
      }
    });
  }