feat: add utilities for typescript ast (#1159)

'ast-utils.ts' provides typescript ast utility functions

addon/ng2/utilities/ast-utils.ts

@@ -0,0 +1,54 @@
+import * as ts from 'typescript';
+import { InsertChange } from './change';
+
+/**
+* Find all nodes from the AST in the subtree of node of SyntaxKind kind.
+* @param node 
+* @param kind
+* @return all nodes of kind kind, or [] if none is found
+*/
+export function findNodes(node: ts.Node, kind: ts.SyntaxKind): ts.Node[] {
+  if (!node) {
+    return [];
+  }
+  let arr: ts.Node[] = [];
+  if (node.kind === kind) {
+    arr.push(node);
+  }
+  return node.getChildren().reduce((foundNodes, child) =>
+                                    foundNodes.concat(findNodes(child, kind)), arr);
+}
+
+/**
+ * Helper for sorting nodes.
+ * @return function to sort nodes in increasing order of position in sourceFile
+ */
+function nodesByPosition(first: ts.Node, second: ts.Node): number {
+  return first.pos - second.pos;
+}
+
+/**
+ * Insert `toInsert` after the last occurence of `ts.SyntaxKind[nodes[i].kind]`
+ * or after the last of occurence of `syntaxKind` if the last occurence is a sub child
+ * of ts.SyntaxKind[nodes[i].kind] and save the changes in file.
+ *  
+ * @param nodes insert after the last occurence of nodes
+ * @param toInsert string to insert
+ * @param file file to insert changes into
+ * @param fallbackPos position to insert if toInsert happens to be the first occurence
+ * @param syntaxKind the ts.SyntaxKind of the subchildren to insert after
+ * @return Change instance
+ * @throw Error if toInsert is first occurence but fall back is not set
+ */
+export function insertAfterLastOccurrence(nodes: ts.Node[], toInsert: string,
+    file: string, fallbackPos?: number, syntaxKind?: ts.SyntaxKind): Change {
+  var lastItem = nodes.sort(nodesByPosition).pop();
+  if (syntaxKind) {
+    lastItem = findNodes(lastItem, syntaxKind).sort(nodesByPosition).pop();
+  }
+  if (!lastItem && fallbackPos == undefined) {
+    throw new Error(`tried to insert ${toInsert} as first occurence with no fallback position`);
+  }
+  let lastItemPosition: number = lastItem ? lastItem.end : fallbackPos;
+  return new InsertChange(file, lastItemPosition, toInsert);
+}

addon/ng2/utilities/dynamic-path-parser.js

@@ -55,4 +55,5 @@ module.exports = function dynamicPathParser(project, entityName) {
   parsedPath.appRoot = appRoot
 
   return parsedPath;
-};
+};
+

tests/acceptance/ast-utils.spec.ts

@@ -0,0 +1,177 @@
+import * as mockFs from 'mock-fs';
+import { expect } from 'chai';
+import * as ts from 'typescript';
+import * as fs from 'fs';
+import { InsertChange, RemoveChange } from '../../addon/ng2/utilities/change';
+import * as Promise from 'ember-cli/lib/ext/promise';
+import {
+  findNodes,
+  insertAfterLastOccurrence
+} from '../../addon/ng2/utilities/ast-utils';
+
+const readFile = Promise.denodeify(fs.readFile);
+
+describe('ast-utils: findNodes', () => {
+  const sourceFile = 'tmp/tmp.ts';
+
+  beforeEach(() => {
+    let mockDrive = {
+      'tmp': {
+        'tmp.ts': `import * as myTest from 'tests' \n` +
+                  'hello.'
+      }
+    };
+    mockFs(mockDrive);
+  });
+
+  afterEach(() => {
+    mockFs.restore();
+  });
+
+  it('finds no imports', () => {
+    let editedFile = new RemoveChange(sourceFile, 0, `import * as myTest from 'tests' \n`);
+    return editedFile
+    .apply()
+    .then(() => {
+      let rootNode = getRootNode(sourceFile);
+      let nodes = findNodes(rootNode, ts.SyntaxKind.ImportDeclaration);
+      expect(nodes).to.be.empty;
+    });
+  });
+  it('finds one import', () => {
+    let rootNode = getRootNode(sourceFile);
+    let nodes = findNodes(rootNode, ts.SyntaxKind.ImportDeclaration);
+    expect(nodes.length).to.equal(1);
+  });
+  it('finds two imports from inline declarations', () => {
+    // remove new line and add an inline import
+    let editedFile = new RemoveChange(sourceFile, 32, '\n');
+    return editedFile
+    .apply()
+    .then(() => {
+      let insert = new InsertChange(sourceFile, 32, `import {Routes} from '@angular/routes'`);
+      return insert.apply();
+    })
+    .then(() => {
+      let rootNode = getRootNode(sourceFile);
+      let nodes = findNodes(rootNode, ts.SyntaxKind.ImportDeclaration);
+      expect(nodes.length).to.equal(2);
+    });
+  });
+  it('finds two imports from new line separated declarations', () => {
+    let editedFile = new InsertChange(sourceFile, 33, `import {Routes} from '@angular/routes'`);
+    return editedFile
+    .apply()
+    .then(() => {
+      let rootNode = getRootNode(sourceFile);
+      let nodes = findNodes(rootNode, ts.SyntaxKind.ImportDeclaration);
+      expect(nodes.length).to.equal(2);
+    });
+  });
+});
+
+describe('ast-utils: insertAfterLastOccurrence', () => {
+  const sourceFile = 'tmp/tmp.ts';
+  beforeEach(() => {
+    let mockDrive = {
+      'tmp': {
+        'tmp.ts': ''
+      }
+    };
+    mockFs(mockDrive);
+  });
+
+  afterEach(() => {
+    mockFs.restore();
+  });
+
+  it('inserts at beginning of file', () => {
+    let imports = getNodesOfKind(ts.SyntaxKind.ImportDeclaration, sourceFile);
+    return insertAfterLastOccurrence(imports, `\nimport { Router } from '@angular/router';`,
+                                    sourceFile, 0)
+    .apply()
+    .then(() => {
+      return readFile(sourceFile, 'utf8');
+    }).then((content) => {
+      let expected = '\nimport { Router } from \'@angular/router\';';
+      expect(content).to.equal(expected);
+    });
+  });
+  it('throws an error if first occurence with no fallback position', () => {
+    let imports = getNodesOfKind(ts.SyntaxKind.ImportDeclaration, sourceFile);
+    expect(() => insertAfterLastOccurrence(imports, `import { Router } from '@angular/router';`,
+                                    sourceFile)).to.throw(Error);
+  });
+  it('inserts after last import', () => {
+    let content = `import { foo, bar } from 'fizz';`;
+    let editedFile = new InsertChange(sourceFile, 0, content);
+    return editedFile
+    .apply()
+    .then(() => {
+      let imports = getNodesOfKind(ts.SyntaxKind.ImportDeclaration, sourceFile);
+      return insertAfterLastOccurrence(imports, ', baz', sourceFile,
+                                      0, ts.SyntaxKind.Identifier)
+             .apply();
+    }).then(() => {
+      return readFile(sourceFile, 'utf8');
+    }).then(newContent => expect(newContent).to.equal(`import { foo, bar, baz } from 'fizz';`));
+  });
+  it('inserts after last import declaration', () => {
+    let content = `import * from 'foo' \n import { bar } from 'baz'`;
+    let editedFile = new InsertChange(sourceFile, 0, content);
+    return editedFile
+    .apply()
+    .then(() => {
+      let imports = getNodesOfKind(ts.SyntaxKind.ImportDeclaration, sourceFile);
+      return insertAfterLastOccurrence(imports, `\nimport Router from '@angular/router'`,
+                                      sourceFile)
+             .apply();
+    }).then(() => {
+      return readFile(sourceFile, 'utf8');
+    }).then(newContent => {
+      let expected = `import * from 'foo' \n import { bar } from 'baz'` +
+                     `\nimport Router from '@angular/router'`;
+      expect(newContent).to.equal(expected);
+    });
+  });
+  it('inserts correctly if no imports', () => {
+    let content = `import {} from 'foo'`;
+    let editedFile = new InsertChange(sourceFile, 0, content);
+    return editedFile
+    .apply()
+   .then(() => {
+     let imports = getNodesOfKind(ts.SyntaxKind.ImportDeclaration, sourceFile);
+     return insertAfterLastOccurrence(imports, ', bar', sourceFile, undefined,
+                                     ts.SyntaxKind.Identifier)
+            .apply();
+   }).catch(() => {
+     return readFile(sourceFile, 'utf8');
+   })
+    .then(newContent => {
+      expect(newContent).to.equal(content);
+      // use a fallback position for safety
+      let imports = getNodesOfKind(ts.SyntaxKind.ImportDeclaration, sourceFile);
+      let pos = findNodes(imports.sort((a, b) => a.pos - b.pos).pop(),
+                          ts.SyntaxKind.CloseBraceToken).pop().pos;
+      return insertAfterLastOccurrence(imports, ' bar ',
+                                      sourceFile, pos, ts.SyntaxKind.Identifier)
+             .apply();
+    }).then(() => {
+      return readFile(sourceFile, 'utf8');
+    }).then(newContent => {
+      expect(newContent).to.equal(`import { bar } from 'foo'`);
+    });
+  });
+});
+
+  /**
+ * Gets node of kind kind from sourceFile
+ */
+function getNodesOfKind(kind: ts.SyntaxKind, sourceFile: string) {
+  return findNodes(getRootNode(sourceFile), kind);
+}
+
+function getRootNode(sourceFile: string) {
+  return ts.createSourceFile(sourceFile, fs.readFileSync(sourceFile).toString(),
+                                         ts.ScriptTarget.ES6, true);
+}