fix(gatsby): use correct stageLabel instead of undefined

packages/gatsby/src/utils/__tests__/__snapshots__/webpack-error-utils.ts.snap

@@ -0,0 +1,77 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`structureWebpackErrors stage: build-html Can't resolve (98124) 1`] = `
+Object {
+  "context": Object {
+    "packageName": "wat.js",
+    "sourceMessage": "Can't resolve 'wat.js' in 'foo.js'",
+    "stage": "build-html",
+    "stageLabel": "Generating SSR bundle",
+  },
+  "filePath": "foo.js",
+  "id": "98124",
+  "location": Object {
+    "start": Object {
+      "column": 10,
+      "line": 5,
+    },
+  },
+}
+`;
+
+exports[`structureWebpackErrors stage: build-javascript Can't resolve (98124) 1`] = `
+Object {
+  "context": Object {
+    "packageName": "wat.js",
+    "sourceMessage": "Can't resolve 'wat.js' in 'foo.js'",
+    "stage": "build-javascript",
+    "stageLabel": "Generating JavaScript bundles",
+  },
+  "filePath": "foo.js",
+  "id": "98124",
+  "location": Object {
+    "start": Object {
+      "column": 10,
+      "line": 5,
+    },
+  },
+}
+`;
+
+exports[`structureWebpackErrors stage: develop Can't resolve (98124) 1`] = `
+Object {
+  "context": Object {
+    "packageName": "wat.js",
+    "sourceMessage": "Can't resolve 'wat.js' in 'foo.js'",
+    "stage": "develop",
+    "stageLabel": "Generating development JavaScript bundle",
+  },
+  "filePath": "foo.js",
+  "id": "98124",
+  "location": Object {
+    "start": Object {
+      "column": 10,
+      "line": 5,
+    },
+  },
+}
+`;
+
+exports[`structureWebpackErrors stage: develop-html Can't resolve (98124) 1`] = `
+Object {
+  "context": Object {
+    "packageName": "wat.js",
+    "sourceMessage": "Can't resolve 'wat.js' in 'foo.js'",
+    "stage": "develop-html",
+    "stageLabel": "Generating development SSR bundle",
+  },
+  "filePath": "foo.js",
+  "id": "98124",
+  "location": Object {
+    "start": Object {
+      "column": 10,
+      "line": 5,
+    },
+  },
+}
+`;

packages/gatsby/src/utils/__tests__/webpack-error-utils.ts

@@ -0,0 +1,32 @@
+import { structureWebpackErrors } from "../webpack-error-utils"
+import { Stage } from "../../commands/types"
+
+describe(`structureWebpackErrors`, () => {
+  const stages: Array<Stage> = [
+    Stage.BuildJavascript,
+    Stage.BuildHTML,
+    Stage.DevelopHTML,
+    Stage.Develop,
+  ]
+
+  describe.each(stages)(`stage: %s`, (stage: Stage) => {
+    it(`Can't resolve (98124)`, () => {
+      const error = new Error(`Can't resolve 'wat.js' in 'foo.js'`) as any
+      error.module = { resource: `foo.js` }
+      error.error = {
+        loc: {
+          line: 5,
+          column: 10,
+        },
+      }
+      let structuredError = structureWebpackErrors(stage, error)
+      if (Array.isArray(structuredError)) {
+        structuredError = structuredError[0]
+      }
+
+      expect(structuredError).toMatchSnapshot()
+      expect(structuredError.context.stageLabel).not.toBeUndefined()
+      expect(structuredError.context.stage).not.toBeUndefined()
+    })
+  })
+})

packages/gatsby/src/utils/webpack-error-utils.ts

@@ -3,15 +3,12 @@ import { Stats } from "webpack"
 import { IMatch } from "../types"
 import { Stage as StageEnum } from "../commands/types"
 
-const stageCodeToReadableLabel = {
-  BuildJavascript: `Generating JavaScript bundles`,
-  BuildHTML: `Generating SSR bundle`,
-  DevelopHTML: `Generating development SSR bundle`,
-  Develop: `Generating development JavaScript bundle`,
-} as const
-
-type Stage = keyof typeof StageEnum
-type StageLabel = typeof stageCodeToReadableLabel[Stage]
+const stageCodeToReadableLabel: Record<StageEnum, string> = {
+  [StageEnum.BuildJavascript]: `Generating JavaScript bundles`,
+  [StageEnum.BuildHTML]: `Generating SSR bundle`,
+  [StageEnum.DevelopHTML]: `Generating development SSR bundle`,
+  [StageEnum.Develop]: `Generating development JavaScript bundle`,
+}
 
 interface ITransformedWebpackError {
   id: string
@@ -21,7 +18,7 @@ interface ITransformedWebpackError {
   }
   context: {
     stage: StageEnum
-    stageLabel: StageLabel
+    stageLabel: string
     sourceMessage?: string
     [key: string]: unknown
   }