diff --git a/index.js b/index.js
index ea23ffb0e..677e1c219 100644
--- a/index.js
+++ b/index.js
@@ -1,17 +1,22 @@
 "use strict";
 
-const comments = require("./src/main/comments");
+const docblock = require("jest-docblock");
+
 const version = require("./package.json").version;
-const printAstToDoc = require("./src/main/ast-to-doc");
+
 const util = require("./src/common/util");
+const getSupportInfo = require("./src/common/support").getSupportInfo;
+
+const comments = require("./src/main/comments");
+const printAstToDoc = require("./src/main/ast-to-doc");
+const normalizeOptions = require("./src/main/options").normalize;
+const parser = require("./src/main/parser");
+
+const config = require("./src/config/resolve-config");
+
 const doc = require("./src/doc");
 const printDocToString = doc.printer.printDocToString;
 const printDocToDebug = doc.debug.printDocToDebug;
-const normalizeOptions = require("./src/common/options").normalize;
-const parser = require("./src/main/parser");
-const config = require("./src/config/resolve-config");
-const getSupportInfo = require("./src/common/support").getSupportInfo;
-const docblock = require("jest-docblock");
 
 function guessLineEnding(text) {
   const index = text.indexOf("\n");
@@ -101,7 +106,7 @@ function formatWithCursor(text, opts, addAlignmentSize) {
 
   let cursorOffset;
   if (opts.cursorOffset >= 0) {
-    const cursorNodeAndParents = findNodeAtOffset(ast, opts.cursorOffset);
+    const cursorNodeAndParents = findNodeAtOffset(ast, opts.cursorOffset, opts);
     const cursorNode = cursorNodeAndParents.node;
     if (cursorNode) {
       cursorOffset = opts.cursorOffset - util.locStart(cursorNode);
@@ -179,16 +184,21 @@ function findSiblingAncestors(startNodeAndParents, endNodeAndParents) {
   };
 }
 
-function findNodeAtOffset(node, offset, predicate, parentNodes) {
+function findNodeAtOffset(node, offset, options, predicate, parentNodes) {
   predicate = predicate || (() => true);
   parentNodes = parentNodes || [];
   const start = util.locStart(node);
   const end = util.locEnd(node);
   if (start <= offset && offset <= end) {
-    for (const childNode of comments.getSortedChildNodes(node)) {
+    for (const childNode of comments.getSortedChildNodes(
+      node,
+      undefined /* text */,
+      options
+    )) {
       const childResult = findNodeAtOffset(
         childNode,
         offset,
+        options,
         predicate,
         [node].concat(parentNodes)
       );
@@ -301,11 +311,17 @@ function calculateRange(text, opts, ast) {
     }
   }
 
-  const startNodeAndParents = findNodeAtOffset(ast, startNonWhitespace, node =>
-    isSourceElement(opts, node)
+  const startNodeAndParents = findNodeAtOffset(
+    ast,
+    startNonWhitespace,
+    opts,
+    node => isSourceElement(opts, node)
   );
-  const endNodeAndParents = findNodeAtOffset(ast, endNonWhitespace, node =>
-    isSourceElement(opts, node)
+  const endNodeAndParents = findNodeAtOffset(
+    ast,
+    endNonWhitespace,
+    opts,
+    node => isSourceElement(opts, node)
   );
 
   if (!startNodeAndParents || !endNodeAndParents) {
@@ -398,6 +414,7 @@ module.exports = {
   /* istanbul ignore next */
   __debug: {
     parse: function(text, opts) {
+      opts = normalizeOptions(opts);
       return parser.parse(text, opts);
     },
     formatAST: function(ast, opts) {
diff --git a/src/cli/util.js b/src/cli/util.js
index 421a6834e..ec7df22c7 100644
--- a/src/cli/util.js
+++ b/src/cli/util.js
@@ -16,7 +16,7 @@ const cleanAST = require("../common/clean-ast").cleanAST;
 const resolver = require("../config/resolve-config");
 const constant = require("./constant");
 const validator = require("./validator");
-const apiDefaultOptions = require("../common/options").defaults;
+const apiDefaultOptions = require("../main/options").defaults;
 const errors = require("../common/errors");
 const logger = require("./logger");
 const thirdParty = require("../common/third-party");
diff --git a/src/common/load-plugins.js b/src/common/load-plugins.js
index 42ef58c27..038050cbf 100644
--- a/src/common/load-plugins.js
+++ b/src/common/load-plugins.js
@@ -12,9 +12,15 @@ function loadPlugins(options) {
     require("../language-markdown"),
     require("../language-html"),
     require("../language-vue")
-  ];
+  ].filter(plugin => {
+    return options.plugins.indexOf(plugin) < 0;
+  });
 
   const externalPlugins = options.plugins.map(plugin => {
+    if (typeof plugin !== "string") {
+      return plugin;
+    }
+
     const pluginPath = resolve.sync(plugin, { basedir: process.cwd() });
     return eval("require")(pluginPath);
   });
diff --git a/src/language-graphql/printer-graphql.js b/src/language-graphql/printer-graphql.js
index c86157440..53b3cf778 100644
--- a/src/language-graphql/printer-graphql.js
+++ b/src/language-graphql/printer-graphql.js
@@ -539,7 +539,24 @@ function printSequence(sequencePath, options, print) {
   });
 }
 
+function canAttachComment(node) {
+  return node.kind && node.kind !== "Comment";
+}
+
+function printComment(commentPath) {
+  const comment = commentPath.getValue();
+
+  switch (comment.kind) {
+    case "Comment":
+      return "#" + comment.value.trimRight();
+    default:
+      throw new Error("Not a comment: " + JSON.stringify(comment));
+  }
+}
+
 module.exports = {
   print: genericPrint,
-  hasPrettierIgnore: util.hasIgnoreComment
+  hasPrettierIgnore: util.hasIgnoreComment,
+  printComment,
+  canAttachComment
 };
diff --git a/src/language-js/printer-estree.js b/src/language-js/printer-estree.js
index 27734bd8c..5e84516d7 100644
--- a/src/language-js/printer-estree.js
+++ b/src/language-js/printer-estree.js
@@ -5167,9 +5167,77 @@ function willPrintOwnComments(path) {
   );
 }
 
+function canAttachComment(node) {
+  return (
+    node.type &&
+    node.type !== "CommentBlock" &&
+    node.type !== "CommentLine" &&
+    node.type !== "Line" &&
+    node.type !== "Block" &&
+    node.type !== "EmptyStatement" &&
+    node.type !== "TemplateElement" &&
+    node.type !== "Import" &&
+    !(node.callee && node.callee.type === "Import")
+  );
+}
+
+function printComment(commentPath, options) {
+  const comment = commentPath.getValue();
+
+  switch (comment.type) {
+    case "CommentBlock":
+    case "Block": {
+      if (isJsDocComment(comment)) {
+        return printJsDocComment(comment);
+      }
+
+      const isInsideFlowComment =
+        options.originalText.substr(util.locEnd(comment) - 3, 3) === "*-/";
+
+      return "/*" + comment.value + (isInsideFlowComment ? "*-/" : "*/");
+    }
+    case "CommentLine":
+    case "Line":
+      // Print shebangs with the proper comment characters
+      if (options.originalText.slice(util.locStart(comment)).startsWith("#!")) {
+        return "#!" + comment.value.trimRight();
+      }
+      return "//" + comment.value.trimRight();
+    default:
+      throw new Error("Not a comment: " + JSON.stringify(comment));
+  }
+}
+
+function isJsDocComment(comment) {
+  const lines = comment.value.split("\n");
+  return (
+    lines.length > 1 &&
+    lines.slice(0, lines.length - 1).every(line => line.trim()[0] === "*")
+  );
+}
+
+function printJsDocComment(comment) {
+  const lines = comment.value.split("\n");
+
+  return concat([
+    "/*",
+    join(
+      hardline,
+      lines.map(
+        (line, index) =>
+          (index > 0 ? " " : "") +
+          (index < lines.length - 1 ? line.trim() : line.trimLeft())
+      )
+    ),
+    "*/"
+  ]);
+}
+
 module.exports = {
   print: genericPrint,
   embed,
   hasPrettierIgnore,
-  willPrintOwnComments
+  willPrintOwnComments,
+  canAttachComment,
+  printComment
 };
diff --git a/src/main/ast-to-doc.js b/src/main/ast-to-doc.js
index d4f333cf5..7ebaa5401 100644
--- a/src/main/ast-to-doc.js
+++ b/src/main/ast-to-doc.js
@@ -12,12 +12,11 @@ const concat = docBuilders.concat;
 const hardline = docBuilders.hardline;
 const addAlignmentToDoc = docBuilders.addAlignmentToDoc;
 const docUtils = doc.utils;
-const getPrinter = require("./get-printer");
 
 function printAstToDoc(ast, options, addAlignmentSize) {
   addAlignmentSize = addAlignmentSize || 0;
 
-  const printer = getPrinter(options);
+  const printer = options.printer;
   const cache = new Map();
 
   function printGenerically(path, args) {
@@ -32,11 +31,11 @@ function printAstToDoc(ast, options, addAlignmentSize) {
     // UnionTypeAnnotation has to align the child without the comments
     let res;
     if (printer.willPrintOwnComments && printer.willPrintOwnComments(path)) {
-      res = genericPrint(path, options, printer, printGenerically, args);
+      res = genericPrint(path, options, printGenerically, args);
     } else {
       res = comments.printComments(
         path,
-        p => genericPrint(p, options, printer, printGenerically, args),
+        p => genericPrint(p, options, printGenerically, args),
         options,
         args && args.needsSemi
       );
@@ -68,10 +67,11 @@ function printAstToDoc(ast, options, addAlignmentSize) {
   return doc;
 }
 
-function genericPrint(path, options, printer, printPath, args) {
+function genericPrint(path, options, printPath, args) {
   assert.ok(path instanceof FastPath);
 
   const node = path.getValue();
+  const printer = options.printer;
 
   // Escape hatch
   if (printer.hasPrettierIgnore && printer.hasPrettierIgnore(path)) {
@@ -81,7 +81,7 @@ function genericPrint(path, options, printer, printPath, args) {
   if (node) {
     try {
       // Potentially switch to a different parser
-      const sub = multiparser.printSubtree(printer, path, printPath, options);
+      const sub = multiparser.printSubtree(path, printPath, options);
       if (sub) {
         return sub;
       }
diff --git a/src/main/comments.js b/src/main/comments.js
index 5c2e1d31c..ad2fe68d6 100644
--- a/src/main/comments.js
+++ b/src/main/comments.js
@@ -18,25 +18,14 @@ const getNextNonSpaceNonCommentCharacter =
 const getNextNonSpaceNonCommentCharacterIndex =
   util.getNextNonSpaceNonCommentCharacterIndex;
 
-function getSortedChildNodes(node, text, resultArray) {
+function getSortedChildNodes(node, text, options, resultArray) {
   if (!node) {
     return;
   }
+  const printer = options.printer;
 
   if (resultArray) {
-    if (
-      node &&
-      ((node.type &&
-        node.type !== "CommentBlock" &&
-        node.type !== "CommentLine" &&
-        node.type !== "Line" &&
-        node.type !== "Block" &&
-        node.type !== "EmptyStatement" &&
-        node.type !== "TemplateElement" &&
-        node.type !== "Import" &&
-        !(node.callee && node.callee.type === "Import")) ||
-        (node.kind && node.kind !== "Comment"))
-    ) {
+    if (node && printer.canAttachComment && printer.canAttachComment(node)) {
       // This reverse insertion sort almost always takes constant
       // time because we almost always (maybe always?) append the
       // nodes in order anyway.
@@ -74,7 +63,7 @@ function getSortedChildNodes(node, text, resultArray) {
   }
 
   for (let i = 0, nameCount = names.length; i < nameCount; ++i) {
-    getSortedChildNodes(node[names[i]], text, resultArray);
+    getSortedChildNodes(node[names[i]], text, options, resultArray);
   }
 
   return resultArray;
@@ -83,8 +72,8 @@ function getSortedChildNodes(node, text, resultArray) {
 // As efficiently as possible, decorate the comment object with
 // .precedingNode, .enclosingNode, and/or .followingNode properties, at
 // least one of which is guaranteed to be defined.
-function decorateComment(node, comment, text) {
-  const childNodes = getSortedChildNodes(node, text);
+function decorateComment(node, comment, text, options) {
+  const childNodes = getSortedChildNodes(node, text, options);
   let precedingNode;
   let followingNode;
   // Time to dust off the old binary search robes and wizard hat.
@@ -101,7 +90,7 @@ function decorateComment(node, comment, text) {
       // The comment is completely contained by this child node.
       comment.enclosingNode = child;
 
-      decorateComment(child, comment, text);
+      decorateComment(child, comment, text, options);
       return; // Abandon the binary search at this level.
     }
 
@@ -174,7 +163,7 @@ function attach(comments, ast, text, options) {
       return;
     }
 
-    decorateComment(ast, comment, text);
+    decorateComment(ast, comment, text, options);
 
     const precedingNode = comment.precedingNode;
     const enclosingNode = comment.enclosingNode;
@@ -923,56 +912,7 @@ function handleVariableDeclaratorComments(
 function printComment(commentPath, options) {
   const comment = commentPath.getValue();
   comment.printed = true;
-
-  switch (comment.type || comment.kind) {
-    case "Comment":
-      return "#" + comment.value.trimRight();
-    case "CommentBlock":
-    case "Block": {
-      if (isJsDocComment(comment)) {
-        return printJsDocComment(comment);
-      }
-
-      const isInsideFlowComment =
-        options.originalText.substr(util.locEnd(comment) - 3, 3) === "*-/";
-
-      return "/*" + comment.value + (isInsideFlowComment ? "*-/" : "*/");
-    }
-    case "CommentLine":
-    case "Line":
-      // Print shebangs with the proper comment characters
-      if (options.originalText.slice(util.locStart(comment)).startsWith("#!")) {
-        return "#!" + comment.value.trimRight();
-      }
-      return "//" + comment.value.trimRight();
-    default:
-      throw new Error("Not a comment: " + JSON.stringify(comment));
-  }
-}
-
-function isJsDocComment(comment) {
-  const lines = comment.value.split("\n");
-  return (
-    lines.length > 1 &&
-    lines.slice(0, lines.length - 1).every(line => line.trim()[0] === "*")
-  );
-}
-
-function printJsDocComment(comment) {
-  const lines = comment.value.split("\n");
-
-  return concat([
-    "/*",
-    join(
-      hardline,
-      lines.map(
-        (line, index) =>
-          (index > 0 ? " " : "") +
-          (index < lines.length - 1 ? line.trim() : line.trimLeft())
-      )
-    ),
-    "*/"
-  ]);
+  return options.printer.printComment(commentPath, options);
 }
 
 function findExpressionIndexForComment(quasis, comment) {
diff --git a/src/common/deprecated.js b/src/main/deprecated.js
similarity index 100%
rename from src/common/deprecated.js
rename to src/main/deprecated.js
diff --git a/src/main/get-printer.js b/src/main/get-printer.js
index 86c7eb925..cba1b1005 100644
--- a/src/main/get-printer.js
+++ b/src/main/get-printer.js
@@ -1,13 +1,14 @@
 "use strict";
 
-const loadPlugins = require("../common/load-plugins");
-const parser = require("./parser");
-
 function getPrinter(options) {
-  const plugins = loadPlugins(options);
-  const parsers = parser.getParsers(plugins, options);
-  const astFormat = parser.resolveParser(parsers, options).astFormat;
-  const printerPlugin = plugins.find(plugin => plugin.printers[astFormat]);
+  const astFormat = options.astFormat;
+
+  if (!astFormat) {
+    throw new Error("getPrinter() requires astFormat to be set");
+  }
+  const printerPlugin = options.plugins.find(
+    plugin => plugin.printers[astFormat]
+  );
   if (!printerPlugin) {
     throw new Error(
       `Couldn't find printer plugin for AST format "${astFormat}"`
diff --git a/src/main/multiparser.js b/src/main/multiparser.js
index 8c635782a..3704e658a 100644
--- a/src/main/multiparser.js
+++ b/src/main/multiparser.js
@@ -1,10 +1,11 @@
 "use strict";
 
+const normalize = require("./options").normalize;
 const comments = require("./comments");
 
-function printSubtree(printer, path, print, options) {
-  if (printer.embed) {
-    return printer.embed(
+function printSubtree(path, print, options) {
+  if (options.printer.embed) {
+    return options.printer.embed(
       path,
       print,
       (text, partialNextOptions) =>
@@ -15,13 +16,12 @@ function printSubtree(printer, path, print, options) {
 }
 
 function textToDoc(text, partialNextOptions, parentOptions) {
-  const nextOptions = Object.assign({}, parentOptions, partialNextOptions, {
-    parentParser: parentOptions.parser,
-    originalText: text
-  });
-  if (nextOptions.parser === "json") {
-    nextOptions.trailingComma = "none";
-  }
+  const nextOptions = normalize(
+    Object.assign({}, parentOptions, partialNextOptions, {
+      parentParser: parentOptions.parser,
+      originalText: text
+    })
+  );
 
   const ast = require("./parser").parse(text, nextOptions);
   const astComments = ast.comments;
diff --git a/src/common/options.js b/src/main/options.js
similarity index 86%
rename from src/common/options.js
rename to src/main/options.js
index b47d8140f..73932f27f 100644
--- a/src/common/options.js
+++ b/src/main/options.js
@@ -4,7 +4,10 @@ const path = require("path");
 
 const validate = require("jest-validate").validate;
 const deprecatedConfig = require("./deprecated");
-const getSupportInfo = require("./support").getSupportInfo;
+const getSupportInfo = require("../common/support").getSupportInfo;
+const loadPlugins = require("../common/load-plugins");
+const resolveParser = require("./parser").resolveParser;
+const getPrinter = require("./get-printer");
 
 const defaults = {
   cursorOffset: -1,
@@ -18,12 +21,16 @@ const defaults = {
   bracketSpacing: true,
   jsxBracketSameLine: false,
   parser: "babylon",
+  parentParser: "",
   insertPragma: false,
   requirePragma: false,
   semi: true,
   proseWrap: "preserve",
   arrowParens: "avoid",
-  plugins: []
+  plugins: [],
+  astFormat: "estree",
+  printer: {},
+  __inJsTemplate: false
 };
 
 const exampleConfig = Object.assign({}, defaults, {
@@ -39,6 +46,7 @@ function normalize(options) {
 
   if (
     filepath &&
+    !normalized.parentParser &&
     (!normalized.parser || normalized.parser === defaults.parser)
   ) {
     const extension = path.extname(filepath);
@@ -114,6 +122,10 @@ function normalize(options) {
     delete normalized.useFlowParser;
   }
 
+  normalized.plugins = loadPlugins(normalized);
+  normalized.astFormat = resolveParser(normalized).astFormat;
+  normalized.printer = getPrinter(normalized);
+
   Object.keys(defaults).forEach(k => {
     if (normalized[k] == null) {
       normalized[k] = defaults[k];
diff --git a/src/main/parser.js b/src/main/parser.js
index 20b25467a..6e04267ad 100644
--- a/src/main/parser.js
+++ b/src/main/parser.js
@@ -2,16 +2,17 @@
 
 const path = require("path");
 const ConfigError = require("../common/errors").ConfigError;
-const loadPlugins = require("../common/load-plugins");
 
-function getParsers(plugins) {
-  return plugins.reduce(
+function getParsers(options) {
+  return options.plugins.reduce(
     (parsers, plugin) => Object.assign({}, parsers, plugin.parsers),
     {}
   );
 }
 
-function resolveParser(parsers, opts) {
+function resolveParser(opts, parsers) {
+  parsers = parsers || getParsers(opts);
+
   if (typeof opts.parser === "function") {
     // Custom parser API always works with JavaScript.
     return {
@@ -39,7 +40,7 @@ function resolveParser(parsers, opts) {
 }
 
 function parse(text, opts) {
-  const parsers = getParsers(loadPlugins(opts), opts);
+  const parsers = getParsers(opts);
 
   // Copy the "parse" function from parser to a new object whose values are
   // functions. Use defineProperty()/getOwnPropertyDescriptor() such that we
@@ -54,7 +55,7 @@ function parse(text, opts) {
     {}
   );
 
-  const parser = resolveParser(parsers, opts);
+  const parser = resolveParser(opts, parsers);
 
   try {
     return parser.parse(text, parsersForCustomParserApi, opts);
@@ -75,4 +76,4 @@ function parse(text, opts) {
   }
 }
 
-module.exports = { getParsers, parse, resolveParser };
+module.exports = { parse, resolveParser };
diff --git a/tests_config/run_spec.js b/tests_config/run_spec.js
index bfc649e58..9baaaff31 100644
--- a/tests_config/run_spec.js
+++ b/tests_config/run_spec.js
@@ -3,7 +3,6 @@
 const fs = require("fs");
 const extname = require("path").extname;
 const prettier = require("./require_prettier");
-const parser = require("../src/main/parser");
 const massageAST = require("../src/common/clean-ast.js").massageAST;
 
 const AST_COMPARE = process.env["AST_COMPARE"];
@@ -116,7 +115,7 @@ function stripLocation(ast) {
 }
 
 function parse(string, opts) {
-  return stripLocation(parser.parse(string, opts));
+  return stripLocation(prettier.__debug.parse(string, opts));
 }
 
 function prettyprint(src, filename, options) {