Tighten up the output of dep node explanations

Reduce visual noise, make the more important information more obvious.

2 files changed, 107 insertions, 60 deletions

diff --git a/lib/utils/explain-dep.js b/lib/utils/explain-dep.js
new file mode 100644
index 000000000..773cc5942
--- /dev/null
+++ b/lib/utils/explain-dep.js
@@ -0,0 +1,101 @@
+const chalk = require('chalk')
+const nocolor = {
+  bold: s => s,
+  dim: s => s,
+  red: s => s,
+  yellow: s => s,
+  cyan: s => s,
+  magenta: s => s
+}
+
+const explainNode = (node, depth, color) =>
+  printNode(node, color) +
+  explainDependents(node, depth, color)
+
+const colorType = (type, color) => {
+  const { red, yellow, cyan, magenta } = color ? chalk : nocolor
+  const style = type === 'extraneous' ? red
+    : type === 'dev' ? yellow
+    : type === 'optional' ? cyan
+    : type === 'peer' ? magenta
+    : /* istanbul ignore next */ s => s
+  return style(type)
+}
+
+const printNode = (node, color) => {
+  const {
+    name,
+    version,
+    location,
+    extraneous,
+    dev,
+    optional,
+    peer
+  } = node
+  const { bold, dim } = color ? chalk : nocolor
+  const extra = []
+  if (extraneous) {
+    extra.push(' ' + bold(colorType('extraneous', color)))
+  }
+  if (dev) {
+    extra.push(' ' + bold(colorType('dev', color)))
+  }
+  if (optional) {
+    extra.push(' ' + bold(colorType('optional', color)))
+  }
+  if (peer) {
+    extra.push(' ' + bold(colorType('peer', color)))
+  }
+
+  return `${bold(name)}@${bold(version)}${extra.join('')}` +
+    (location ? dim(`\n${location}`) : '')
+}
+
+const explainDependents = ({ name, dependents }, depth, color) => {
+  if (!dependents || !dependents.length || depth <= 0) {
+    return ''
+  }
+
+  const max = Math.ceil(depth / 2)
+  const messages = dependents.slice(0, max)
+    .map(dep => explainDependency(name, dep, depth, color))
+
+  // show just the names of the first 5 deps that overflowed the list
+  if (dependents.length > max) {
+    let len = 0
+    const maxLen = 30
+    const showNames = []
+    for (let i = max; i < dependents.length; i++) {
+      const { from: { name } } = dependents[i]
+      len += name.length
+      if (len >= maxLen && i < dependents.length - 1) {
+        showNames.push('...')
+        break
+      }
+      showNames.push(name)
+    }
+    const show = `(${showNames.join(', ')})`
+    messages.push(`${dependents.length - max} more ${show}`)
+  }
+
+  const str = '\n' + messages.join('\n')
+  return str.split('\n').join('\n  ')
+}
+
+const explainDependency = (name, { type, from, spec }, depth, color) => {
+  const { bold } = color ? chalk : nocolor
+  return (type === 'prod' ? '' : `${colorType(type, color)} `) +
+    `${bold(name)}@"${bold(spec)}" from ` +
+    explainFrom(from, depth, color)
+}
+
+const explainFrom = (from, depth, color) => {
+  if (!from.name && !from.version) {
+    return 'the root project'
+  }
+
+  return printNode(from, color) +
+    explainDependents(from, depth - 1, color)
+}
+
+module.exports = { explainNode, printNode }
diff --git a/lib/utils/explain-eresolve.js b/lib/utils/explain-eresolve.js
index 65a62a115..51a856f6c 100644
--- a/lib/utils/explain-eresolve.js
+++ b/lib/utils/explain-eresolve.js
@@ -8,12 +8,7 @@
 const npm = require('../npm.js')
 const { writeFileSync } = require('fs')
 const { resolve } = require('path')
-
-const chalk = require('chalk')
-const nocolor = {
-  bold: s => s,
-  dim: s => s
-}
+const { explainNode, printNode } = require('./explain-dep.js')
 
 // expl is an explanation object that comes from Arborist.  It looks like:
 // {
@@ -50,69 +45,20 @@ const explainEresolve = (expl, color, depth) => {
     out.push('While resolving: ' + printNode(dep.whileInstalling, color))
   }
 
-  out.push(explainNode('Found:', current, depth, color))
+  out.push('Found: ' + explainNode(current, depth, color))
 
-  out.push(explainNode('\nCould not add conflicting dependency:', dep, depth, color))
+  out.push('\nCould not add conflicting dependency: ' +
+    explainNode(dep, depth, color))
 
   if (peerConflict) {
     const heading = '\nConflicting peer dependency:'
-    const pc = explainNode(heading, peerConflict, depth, color)
-    out.push(pc)
+    const pc = explainNode(peerConflict, depth, color)
+    out.push(heading + ' ' + pc)
   }
 
   return out.join('\n')
 }
 
-const explainNode = (heading, node, depth, color) =>
-  `${heading} ${printNode(node, color)}` +
-  explainDependents(node, depth, color)
-
-const printNode = ({ name, version, location }, color) => {
-  const { bold, dim } = color ? chalk : nocolor
-  return `${bold(name)}@${bold(version)}` +
-    (location ? dim(` at ${location}`) : '')
-}
-
-const explainDependents = ({ name, dependents }, depth, color) => {
-  if (!dependents || !dependents.length || depth <= 0) {
-    return ''
-  }
-
-  const max = Math.ceil(depth / 2)
-  const messages = dependents.slice(0, max)
-    .map(dep => explainDependency(name, dep, depth, color))
-
-  // show just the names of the first 5 deps that overflowed the list
-  if (dependents.length > max) {
-    const names = dependents.slice(max).map(d => d.from.name)
-    const showNames = names.slice(0, 5)
-    if (showNames.length < names.length) {
-      showNames.push('...')
-    }
-    const show = `(${showNames.join(', ')})`
-    messages.push(`${names.length} more ${show}`)
-  }
-
-  const str = '\nfor: ' + messages.join('\nand: ')
-  return str.split('\n').join('\n  ')
-}
-
-const explainDependency = (name, { type, from, spec }, depth, color) => {
-  const { bold } = color ? chalk : nocolor
-  return `${type} dependency ` +
-    `${bold(name)}@"${bold(spec)}"\nfrom: ` +
-    explainFrom(from, depth, color)
-}
-
-const explainFrom = (from, depth, color) => {
-  if (!from.name && !from.version) {
-    return 'the root project'
-  }
-
-  return printNode(from, color) +
-    explainDependents(from, depth - 1, color)
-}
-
 // generate a full verbose report and tell the user how to fix it
 const report = (expl, depth = 4) => {
   const fullReport = resolve(npm.cache, 'eresolve-report.txt')