feat: head command against vfs

myan9 · starpit · commit 03e3f8a59ef6 · 2021-02-15T16:08:56.000-05:00
Fixes #7012
diff --git a/packages/test/src/api/selectors.ts b/packages/test/src/api/selectors.ts
@@ -86,6 +86,8 @@ export const SIDECAR_TAB_CONTENT = (N: number, splitIndex = 1) =>
   `${SIDECAR(N, splitIndex)} .kui--tab-content:not([hidden]) .custom-content`
 export const SIDECAR_CUSTOM_CONTENT = (N: number, splitIndex = 1) =>
   `${SIDECAR_TAB_CONTENT(N, splitIndex)} .code-highlighting`
+export const SIDECAR_CUSTOM_CONTENT_LINE_NUMBERS = (N: number, splitIndex = 1) =>
+  `${SIDECAR_TAB_CONTENT(N, splitIndex)} .code-highlighting .line-numbers`
 
 // top nav sidecar
 export const SIDECAR_MODE_BUTTONS = (N: number, splitIndex = 1) =>
diff --git a/plugins/plugin-bash-like/fs/src/lib/head.ts b/plugins/plugin-bash-like/fs/src/lib/head.ts
@@ -0,0 +1,104 @@
+/*
+ * Copyright 2021 IBM Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import Debug from 'debug'
+import { basename, dirname } from 'path'
+
+import {
+  findFile,
+  expandHomeDir,
+  i18n,
+  MultiModalResponse,
+  Arguments,
+  Registrar,
+  KResponse,
+  ParsedOptions
+} from '@kui-shell/core'
+import File from './File'
+import { contentTypeOf } from './open'
+import { fslice } from '../vfs/delegates'
+
+const strings = i18n('plugin-bash-like')
+const debug = Debug('plugins/bash-like/cmds/head')
+
+interface HeadOptions extends ParsedOptions {
+  n: number // line counts
+  c: number // bytes
+}
+
+export function showResponseAsMMR(filepath: string, data: string): MultiModalResponse {
+  const suffix = filepath.substring(filepath.lastIndexOf('.') + 1)
+  const enclosingDirectory = dirname(filepath)
+  const packageName = enclosingDirectory === '.' ? undefined : enclosingDirectory
+
+  const mode = {
+    mode: 'view',
+    label: strings('View'),
+    contentType: contentTypeOf(suffix),
+    content: data
+  }
+
+  const response: MultiModalResponse<File> = {
+    apiVersion: 'kui-shell/v1',
+    kind: 'File',
+    metadata: {
+      name: basename(filepath),
+      namespace: packageName
+    },
+    modes: [mode],
+    spec: {
+      filepath,
+      fullpath: findFile(expandHomeDir(filepath))
+    }
+  }
+
+  return response
+}
+
+async function head(args: Arguments<HeadOptions>): Promise<KResponse> {
+  const { argvNoOptions, parsedOptions } = args
+  const filepath = argvNoOptions[argvNoOptions.indexOf('head') + 1]
+  debug('head', filepath)
+
+  if (typeof filepath === 'number' && filepath < 0) {
+    // special case for command: e.g. head -10 file
+    // change `head -10 file` to `head -n 10 file`
+    const newarg = `-n ${filepath * -1}`
+    return args.REPL.qexec(args.command.replace(filepath, newarg))
+  }
+
+  try {
+    const data = await fslice(
+      filepath,
+      0,
+      parsedOptions.c || parsedOptions.n || 10,
+      parsedOptions.c ? 'bytes' : 'lines'
+    )
+    return showResponseAsMMR(filepath, data)
+  } catch (err) {
+    throw new Error(`head: ${err.message}`)
+  }
+}
+
+/**
+ * Register command handlers
+ *
+ */
+export default (registrar: Registrar) => {
+  registrar.listen('/head', head, {
+    requiresLocal: true
+  })
+}
diff --git a/plugins/plugin-bash-like/fs/src/lib/open.ts b/plugins/plugin-bash-like/fs/src/lib/open.ts
@@ -37,7 +37,7 @@ const strings = i18n('plugin-bash-like')
 const debug = Debug('plugins/bash-like/cmds/open')
 
 /** Important for alignment to the Editor view component */
-function contentTypeOf(suffix: string): SupportedStringContent {
+export function contentTypeOf(suffix: string): SupportedStringContent {
   switch (suffix) {
     case 'sh':
       return 'shell'
diff --git a/plugins/plugin-bash-like/fs/src/plugin.ts b/plugins/plugin-bash-like/fs/src/plugin.ts
@@ -17,6 +17,7 @@
 import cd from './lib/cd'
 import ls from './lib/ls'
 import edit from './lib/edit'
+import head from './lib/head'
 import open from './lib/open'
 import fwrite from './lib/fwrite'
 import mkTemp from './lib/mkTemp'
@@ -34,6 +35,7 @@ export default async (registrar: Registrar) => {
     cd(registrar),
     ls(registrar),
     edit(registrar),
+    head(registrar),
     open(registrar),
     fwrite(registrar),
     mkTemp(registrar),
diff --git a/plugins/plugin-bash-like/fs/src/vfs/delegates.ts b/plugins/plugin-bash-like/fs/src/vfs/delegates.ts
@@ -218,6 +218,54 @@ export async function fstat(...parameters: Parameters<VFS['fstat']>): ReturnType
   return mount.fstat(parameters[0], parameters[1], parameters[2], parameters[3])
 }
 
+/**
+ * fslice delegate
+ *
+ */
+export async function fslice(
+  filepath: string,
+  offsetAsProvided: number,
+  length: number,
+  unit: 'bytes' | 'lines'
+): ReturnType<VFS['fslice']> {
+  const mount = findMount(filepath, undefined, true)
+
+  if (!mount) {
+    throw new Error(`head: can not find ${filepath}`)
+  }
+
+  if (unit === 'bytes') {
+    return mount.fslice(filepath, offsetAsProvided, length)
+  } else {
+    let offset = offsetAsProvided
+    let dataRead = ''
+    while (true) {
+      try {
+        const data = await mount.fslice(filepath, offset, 1000000)
+        if (data) {
+          dataRead = dataRead.concat(data)
+          const lines = dataRead.split('\n')
+
+          if (lines.length >= length) {
+            dataRead = lines.slice(0, length).join('\n')
+            break
+          } else {
+            offset = Buffer.from(dataRead).length
+          }
+        } else {
+          console.error('bash-like fslice: no data read')
+          break
+        }
+      } catch (err) {
+        console.error(err)
+        break
+      }
+    }
+
+    return dataRead
+  }
+}
+
 /**
  * mkdir delegate
  *
diff --git a/plugins/plugin-bash-like/fs/src/vfs/index.ts b/plugins/plugin-bash-like/fs/src/vfs/index.ts
@@ -97,6 +97,9 @@ export interface VFS {
     enoentOk?: boolean
   ): Promise<FStat>
 
+  /** Fetch content slice */
+  fslice(filename: string, offset: number, length: number): Promise<string>
+
   /** Create a directory/bucket */
   mkdir(
     opts: Pick<Arguments, 'command' | 'REPL' | 'argvNoOptions' | 'parsedOptions' | 'execOptions'>,
diff --git a/plugins/plugin-bash-like/fs/src/vfs/local.ts b/plugins/plugin-bash-like/fs/src/vfs/local.ts
@@ -14,7 +14,8 @@
  * limitations under the License.
  */
 
-import { Arguments, encodeComponent } from '@kui-shell/core'
+import { open, read, stat } from 'fs'
+import { Arguments, encodeComponent, expandHomeDir, findFileWithViewer } from '@kui-shell/core'
 
 import { VFS, mount } from '.'
 import { kuiglob, KuiGlobOptions } from '../lib/glob'
@@ -67,6 +68,39 @@ class LocalVFS implements VFS {
     })
   }
 
+  /** Fetch content slice */
+  public async fslice(filepath: string, offset: number, _length: number): Promise<string> {
+    const { resolved: fullpath } = findFileWithViewer(expandHomeDir(filepath))
+
+    return new Promise((resolve, reject) => {
+      open(fullpath, 'r', (err, fd) => {
+        if (err) {
+          reject(err)
+        } else {
+          stat(fullpath, (err, stats) => {
+            if (err) reject(err)
+            try {
+              if (offset >= stats.size) {
+                reject(new Error('local fslice: reach file end'))
+              } else {
+                const length = _length <= stats.size ? _length : stats.size
+                read(fd, Buffer.alloc(length), 0, length, offset, (_err, _, buff) => {
+                  if (_err) {
+                    reject(_err)
+                  } else {
+                    resolve(buff.toString())
+                  }
+                })
+              }
+            } catch (err) {
+              reject(err)
+            }
+          })
+        }
+      })
+    })
+  }
+
   /** Create a directory/bucket */
   public async mkdir(opts: Pick<Arguments, 'command' | 'REPL' | 'parsedOptions' | 'execOptions'>): Promise<void> {
     await opts.REPL.qexec(
diff --git a/plugins/plugin-bash-like/src/test/bash-like/head.ts b/plugins/plugin-bash-like/src/test/bash-like/head.ts
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2017-19 IBM Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { dirname, join } from 'path'
+
+import { Common, CLI, ReplExpect, Selectors, SidecarExpect, Util } from '@kui-shell/test'
+
+const ROOT = dirname(require.resolve('@kui-shell/core/tests/package.json'))
+const rootRelative = (dir: string) => join(ROOT, dir)
+
+describe(`bash-like head ${process.env.MOCHA_RUN_TARGET || ''}`, function(this: Common.ISuite) {
+  before(Common.before(this))
+  after(Common.after(this))
+
+  it('should head package.json and see 10 lines', () =>
+    CLI.command(`head ${rootRelative('package.json')}`, this.app)
+      .then(ReplExpect.ok)
+      .then(SidecarExpect.open)
+      .then(res =>
+        this.app.client.waitUntil(async () => {
+          const linesNumbers = await this.app.client.$$(
+            Selectors.SIDECAR_CUSTOM_CONTENT_LINE_NUMBERS(res.count, res.splitIndex)
+          )
+          return linesNumbers.length === 10
+        })
+      )
+      .catch(Common.oops(this)))
+
+  it('should head -n 5 package.json and see 5 lines', () =>
+    CLI.command(`head -n 5 ${rootRelative('package.json')}`, this.app)
+      .then(ReplExpect.ok)
+      .then(SidecarExpect.open)
+      .then(res =>
+        this.app.client.waitUntil(async () => {
+          const linesNumbers = await this.app.client.$$(
+            Selectors.SIDECAR_CUSTOM_CONTENT_LINE_NUMBERS(res.count, res.splitIndex)
+          )
+          return linesNumbers.length === 5
+        })
+      )
+      .catch(Common.oops(this)))
+
+  it('should head -c 1 package.json and see 1 bytes', () =>
+    CLI.command(`head -c 1 ${rootRelative('package.json')}`, this.app)
+      .then(ReplExpect.ok)
+      .then(SidecarExpect.open)
+      .then(res =>
+        this.app.client.waitUntil(async () => {
+          const value = await Util.getValueFromMonaco(res)
+          const bufferSize = Buffer.from(value).length
+          return bufferSize === 1
+        })
+      )
+      .catch(Common.oops(this)))
+
+  it('should head /kui/welcome.json and see 10 lines', () =>
+    CLI.command('head /kui/welcome.json', this.app)
+      .then(ReplExpect.ok)
+      .then(SidecarExpect.open)
+      .then(res =>
+        this.app.client.waitUntil(async () => {
+          const linesNumbers = await this.app.client.$$(
+            Selectors.SIDECAR_CUSTOM_CONTENT_LINE_NUMBERS(res.count, res.splitIndex)
+          )
+          return linesNumbers.length === 10
+        })
+      )
+      .catch(Common.oops(this)))
+
+  it('should head -n 5 /kui/welcome.json and see 5 lines', () =>
+    CLI.command('head -n 5 /kui/welcome.json', this.app)
+      .then(ReplExpect.ok)
+      .then(SidecarExpect.open)
+      .then(res =>
+        this.app.client.waitUntil(async () => {
+          const linesNumbers = await this.app.client.$$(
+            Selectors.SIDECAR_CUSTOM_CONTENT_LINE_NUMBERS(res.count, res.splitIndex)
+          )
+          return linesNumbers.length === 5
+        })
+      )
+      .catch(Common.oops(this)))
+
+  it('should head -c 1 /kui/welcome.json and see 1 bytes', () =>
+    CLI.command('head -c 1 /kui/welcome.json', this.app)
+      .then(ReplExpect.ok)
+      .then(SidecarExpect.open)
+      .then(res =>
+        this.app.client.waitUntil(async () => {
+          const value = await Util.getValueFromMonaco(res)
+          const bufferSize = Buffer.from(value).length
+          return bufferSize === 1
+        })
+      )
+      .catch(Common.oops(this)))
+})
diff --git a/plugins/plugin-core-support/src/notebooks/vfs/index.ts b/plugins/plugin-core-support/src/notebooks/vfs/index.ts
@@ -225,6 +225,21 @@ export class NotebookVFS implements VFS {
     }
   }
 
+  /** Fetch content slice */
+  public async fslice(filename: string, offset: number, length: number): Promise<string> {
+    const entry = this.findExact(filename, true)
+    if (entry.data) {
+      const buffer = Buffer.from(entry.data)
+      if (offset > buffer.length) {
+        throw new Error(`notebook fslice: reach file end`)
+      } else {
+        return buffer.slice(offset, length + offset).toString()
+      }
+    } else {
+      throw new Error(`fslice: data not found ${filename}`)
+    }
+  }
+
   /** Create a directory/bucket */
   public async mkdir(opts: Pick<Arguments, 'argvNoOptions'>): Promise<void> {
     const mountPath = opts.argvNoOptions[opts.argvNoOptions.indexOf('mkdir') + 1]
