CovidSim connector: Add integration tests for regional parameter files

These are tightly tied to the model's data directory paths, and the connector writes to the input file directory.
Hence these are added as integration rather than unit tests.

packages/mrc-ide-covidsim/test/integration/imperial-integration-test.ts

@@ -1,11 +1,100 @@
-import * as temp from 'temp'
 import * as fs from 'fs'
+import * as path from 'path'
+import * as temp from 'temp'
 import { assert } from 'chai'
 import { ImperialModel } from '../../src/imperial'
 import { BIN_DIR, MODEL_DATA_DIR } from '../../src/config'
 import { input } from '@covid-modeling/api'
 
 suite('imperial integration', () => {
+  const testRegions = [
+    {
+      region: 'CA',
+      subregion: undefined,
+      expectedAdminPath: 'Canada_admin.txt',
+      expectedPopulationDensityPath: 'wpop_usacan.txt',
+      expectedPreParameterPath: 'preUK_R0=2.0.txt',
+    },
+    {
+      region: 'NG',
+      subregion: undefined,
+      expectedAdminPath: 'Nigeria_admin.txt',
+      expectedPopulationDensityPath: 'wpop_eur.txt',
+      expectedPreParameterPath: 'preNG_R0=2.0.txt',
+    },
+    {
+      region: 'RU',
+      subregion: undefined,
+      expectedAdminPath: 'Russia_admin.txt',
+      expectedPopulationDensityPath: 'wpop_eur.txt',
+      expectedPreParameterPath: 'preUK_R0=2.0.txt',
+    },
+    {
+      region: 'GB',
+      subregion: undefined,
+      expectedAdminPath: 'United_Kingdom_admin.txt',
+      expectedPopulationDensityPath: 'wpop_eur.txt',
+      expectedPreParameterPath: 'preUK_R0=2.0.txt',
+    },
+    {
+      region: 'US',
+      subregion: undefined,
+      expectedAdminPath: 'United_States_admin.txt',
+      expectedPopulationDensityPath: 'wpop_usacan.txt',
+      expectedPreParameterPath: 'preUS_R0=2.0.txt',
+    },
+    {
+      region: 'US',
+      subregion: 'US-NY',
+      expectedAdminPath: 'admin-params.txt',
+      expectedPopulationDensityPath: 'wpop_usacan.txt',
+      expectedPreParameterPath: 'preUS_R0=2.0.txt',
+    },
+  ]
+  testRegions.forEach(testRegion => {
+    test(`finds parameter files for region ${testRegion.region} and subregion ${testRegion.subregion}`, () => {
+      const modelInput: input.ModelInput = {
+        region: testRegion.region,
+        subregion: testRegion.subregion,
+        parameters: {
+          calibrationDate: '2020-03-20',
+          calibrationCaseCount: 500,
+          calibrationDeathCount: 120,
+          r0: null,
+          interventionPeriods: [],
+        },
+      }
+
+      const logDir = temp.mkdirSync()
+      const inputDir = temp.mkdirSync()
+      const outputDir = temp.mkdirSync()
+      const binDir = temp.mkdirSync()
+
+      const model = new ImperialModel(
+        1,
+        binDir,
+        logDir,
+        MODEL_DATA_DIR,
+        inputDir,
+        outputDir
+      )
+
+      const runnerModelInput = model.inputs(modelInput)
+      assert.equal(
+        runnerModelInput.adminFilePath,
+        path.join(inputDir, testRegion.expectedAdminPath)
+      )
+      assert.equal(
+        runnerModelInput.populationDensityFilePath,
+        path.join(
+          MODEL_DATA_DIR,
+          'populations',
+          testRegion.expectedPopulationDensityPath
+        )
+      )
+    })
+  })
+
   test('run imperial model for Wyoming', async () => {
     const logDir = temp.mkdirSync()
     const inputDir = temp.mkdirSync()