[gatsby-source-filesystem] add publicURL field

packages/gatsby-source-filesystem/src/extend-file-node.js

@@ -0,0 +1,44 @@
+const { GraphQLString } = require(`graphql`)
+const fs = require(`fs-extra`)
+const path = require(`path`)
+
+module.exports = ({ type, getNodeAndSavePathDependency, pathPrefix = "" }) => {
+  if (type.name !== `File`) {
+    return {}
+  }
+
+  return {
+    publicURL: {
+      type: GraphQLString,
+      args: {},
+      resolve: (file, fieldArgs, context) => {
+        const details = getNodeAndSavePathDependency(file.id, context.path)
+        const fileName = `${file.name}-${file.internal.contentDigest}${
+          details.ext
+        }`
+
+        const publicPath = path.join(
+          process.cwd(),
+          `public`,
+          `static`,
+          fileName
+        )
+
+        if (!fs.existsSync(publicPath)) {
+          fs.copy(details.absolutePath, publicPath, err => {
+            if (err) {
+              console.error(
+                `error copying file from ${
+                  details.absolutePath
+                } to ${publicPath}`,
+                err
+              )
+            }
+          })
+        }
+
+        return `${pathPrefix}/static/${fileName}`
+      },
+    },
+  }
+}

packages/gatsby-source-filesystem/src/gatsby-node.js

@@ -95,3 +95,5 @@ Please pick a path to an existing directory.
     })
   })
 }
+
+exports.setFieldsOnGraphQLNodeType = require(`./extend-file-node`)

packages/gatsby-transformer-sharp/src/extend-node-type.js

@@ -115,25 +115,33 @@ module.exports = ({ type, pathPrefix, getNodeAndSavePathDependency }) => {
       async resolve(image, fieldArgs, context) {
         const details = getNodeAndSavePathDependency(image.parent, context.path)
         const dimensions = sizeOf(details.absolutePath)
-        const imageName = `${image.internal.contentDigest}${details.ext}`
+        const imageName = `${details.name}-${image.internal.contentDigest}${
+          details.ext
+        }`
         const publicPath = path.join(
           process.cwd(),
           `public`,
-          `static/${imageName}`
+          `static`,
+          imageName
         )
 
         if (!fsExtra.existsSync(publicPath)) {
           fsExtra.copy(details.absolutePath, publicPath, err => {
             if (err) {
-              console.error(`error copying file`, err)
+              console.error(
+                `error copying file from ${
+                  details.absolutePath
+                } to ${publicPath}`,
+                err
+              )
             }
           })
         }
 
         return {
           width: dimensions.width,
           height: dimensions.height,
-          src: `/static/` + imageName,
+          src: `${pathPrefix}/static/${imageName}`,
         }
       },
     },