refactor(mocks): load the webout guard as a module, not by eval

The guard is the tree's one shared rule, but each of the three services that
needs it repeated the path derivation and then eval'd a file read out of the
SASjs Drive at run time - which is what the file's own header said this tree does
not need.  weboutGuard.js now exports the function and the services require it by
absolute path: one copy of the function, no eval, and a load failure is a
require error naming the file rather than a silent no-op.

Being a module also means the guard has to carry its own dependencies: as an
eval'd snippet `fs` came from the program's scope, and the first run as a
required module failed with "fs is not defined".  It now requires fs itself.

dcMockUtils.requireMemberMetadata remains the source of truth for the rule and
both files say so, since a site may run both trees and an operator reads
whichever one threw.

sas/mocks/sas9/sasjs/services/editors/getdata.js

@@ -3,17 +3,14 @@ const nodePath = require('path')
 const appLoc = nodePath.join(..._program.split('services')[0].split('/'))
 const sasjsRoot = nodePath.resolve(weboutPath, '..', '..', '..')
 
-eval(
-  fs.readFileSync(
-    nodePath.resolve(
-      sasjsRoot,
-      'drive',
-      'files',
-      appLoc,
-      'services',
-      'weboutGuard.js'
-    ),
-    'utf8'
+const requireMemberMetadata = require(
+  nodePath.resolve(
+    sasjsRoot,
+    'drive',
+    'files',
+    appLoc,
+    'services',
+    'weboutGuard.js'
   )
 )
 

sas/mocks/sas9/sasjs/services/public/getcolvals.js

@@ -3,17 +3,14 @@ const nodePath = require('path')
 const appLoc = nodePath.join(..._program.split('services')[0].split('/'))
 const sasjsRoot = nodePath.resolve(weboutPath, '..', '..', '..')
 
-eval(
-  fs.readFileSync(
-    nodePath.resolve(
-      sasjsRoot,
-      'drive',
-      'files',
-      appLoc,
-      'services',
-      'weboutGuard.js'
-    ),
-    'utf8'
+const requireMemberMetadata = require(
+  nodePath.resolve(
+    sasjsRoot,
+    'drive',
+    'files',
+    appLoc,
+    'services',
+    'weboutGuard.js'
   )
 )
 

sas/mocks/sas9/sasjs/services/public/viewdata.js

@@ -3,17 +3,14 @@ const nodePath = require('path')
 const appLoc = nodePath.join(..._program.split('services')[0].split('/'))
 const sasjsRoot = nodePath.resolve(weboutPath, '..', '..', '..')
 
-eval(
-  fs.readFileSync(
-    nodePath.resolve(
-      sasjsRoot,
-      'drive',
-      'files',
-      appLoc,
-      'services',
-      'weboutGuard.js'
-    ),
-    'utf8'
+const requireMemberMetadata = require(
+  nodePath.resolve(
+    sasjsRoot,
+    'drive',
+    'files',
+    appLoc,
+    'services',
+    'weboutGuard.js'
   )
 )
 

sas/mocks/sas9/sasjs/services/weboutGuard.js

@@ -2,11 +2,12 @@
  * @file weboutGuard.js
  * @brief Refuse a webout() member whose column metadata did not reach the response.
  *
- * The sasjs tree keeps this beside its other shared utilities in
- * `sas/mocks/sasjs/services/dcMockUtils.js`; this tree is one file per service
- * with no shared module, so the services that pass `{ showmeta }` - getdata,
- * getcolvals and viewdata - load this file instead, to keep the rule in one
- * place rather than copied into each of them.
+ * This is the sas9 tree's copy of the rule, and `requireMemberMetadata` in
+ * `sas/mocks/sasjs/services/dcMockUtils.js` is the source of truth for it: the
+ * two must say the same thing, because an operator reads whichever one their
+ * tree throws and a site may run both.  The services that pass `{ showmeta }` -
+ * getdata, getcolvals and viewdata - require this file rather than repeating
+ * the check.
  *
  * Call it immediately after the `webout('OBJ', ...)` that carried the option,
  * and before `webout('CLOSE')`: a throw after CLOSE leaves a complete body
@@ -24,6 +25,8 @@
  * @param {string} bodyPath the response body the program is writing
  * @param {string} member the member the caller wrote
  */
+const fs = require('fs')
+
 function requireMemberMetadata(bodyPath, member) {
   let body
   try {
@@ -57,3 +60,5 @@ function requireMemberMetadata(bodyPath, member) {
       'later, on the host running this program.'
   )
 }
+
+module.exports = requireMemberMetadata

sas/mocks/sasjs/services/dcMockUtils.js

@@ -46,8 +46,9 @@ const MONTHS_NUM = {JAN:'01',FEB:'02',MAR:'03',APR:'04',MAY:'05',JUN:'06',JUL:'0
  * `@sasjs/server`'s `^4.4.0` range can resolve on releases before 3.12.3 -
  * writes the rows and drops the metadata silently. The response still looks
  * complete, so the estate quietly tests less than it claims. Refuse it instead,
- * and name the cause. The sas9 tree carries the same function in
- * `sas/mocks/sas9/sasjs/services/weboutGuard.js`; keep the two saying one thing.
+ * and name the cause. This function is the source of truth for the rule; the
+ * sas9 tree's `sas/mocks/sas9/sasjs/services/weboutGuard.js` is a copy of it and
+ * the two must say one thing, because an operator reads whichever tree threw.
  *
  * Testing the output rather than the function is deliberate: an arity check
  * (`webout.length`) stops counting at the first default or rest parameter, so a